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Conferva or Zygnema, it is doubtful which from the condition of the specimens; and at the

same elevation, in the nearly dry bed of the stream which flows from the larger lake at Momay, amongst flat cakes, consisting of

felspathic silt from the glaciers above, and the debris of Algae, and abounding in Diatomaceae, some threads of a Zygnema. At 17,000

feet, an Oscillatoria, attached or adherent to Zannichellia; and, finally, on the bare ground, at 18,000 feet, on the Donkia mountains, an obscure species of Caenocoleus. On the surface of the glaciers at Kinchinjhow, on silt, there is a curious Palmella, apparently

quite distinct from any European form.

Amongst the greater part of the Algae, from 4000 feet to 18,000 feet, various Diatomaceae occur, which will be best noticed in a tabular

form, as follows; the specific name, within brackets, merely

indicating the species to which they bear most resemblance:--

Himantidium (Soleirolii) 4000 to 7000 ft. Sikkim

Odontidium (hiemale, forma minor) 5000 to 7000 ft. Sikkim

Epithemia, n. sp. 7000 ft. Sikkim

Cymbella -- Sikkim

Navicula, n. sp. -- Sikkim

Tabillaria (flocculosa) 6000 to 7000 ft. Sikkim

Odontidium (hiemale) 11,000 ft. Sikkim

Himantidium 16,000 ft. Momay

Odontidium (turgidulum) 17,000 ft. Momay

Epithemia (ocellata) -- Tibet

Fragillaria 18,000 ft. Momay

Odontidium (turgidulum) -- Momay

Dictyocha (gracilis) -- Momay

Odontidium (hiemale) -- Kinchinjhow

We now turn to those portions of Tibet or the neighbouring regions, explored by Dr. Thomson and Captain Strachey. The principal feature in the Algology is the great prevalence of species of Zygnema and Tyndaridea, which occur under a variety of forms, sometimes with

very thick gelatinous coats. In not a single instance, however, is

there the slightest tendency to produce fructification. _Conferva

crispata_ again, as mentioned above, occurs in several localities;

and in one locality a beautiful unbranched Conferva, with torulose articulations. At Iskardo, Dr. Thomson gathered a very gelatinous

species of Draparnaldia, or more properly, a Stygeoclonium, if we may judge from a little conglomeration of cells which appeared

amongst the threads. A Tetraspora in Piti, an obscure

Tolypothrix, and one or two Oscillatoriae, remarkable for their interrupted mode of growth, complete the list of Algae, with the

exception of one, to be mentioned presently; as also of

Diatomaceae, and of the species of Nostoc and Hormosiphon,

which occurred in great profusion, and under several forms, sometimes attaining a very large size (several inches across), especially in

the districts of Le and Piti, and where the soil or waters were

impregnated with saline matters. It is well known that some species of Nostoc form an article of food in China, and one was used for

that purpose in a late Arctic expedition, as reported by Dr.

Sutherland; but it does not seem that any use is made of them in

Tibet, though probably all the large species would form tolerable

articles of food, and certainly, from their chemical composition,

prove very nutritious. One species is mentioned by Dr. Thomson as

floating, without any attachment, in the shallow water of the pools scattered over the plains, on the Parang River, separated only by a ridge of mountains from Piti, broad and foliaceous, and scarcely

different from the common Nostoc, which occurs in all parts of the globe. I must not, however, neglect to record a very singular new

genus, in which the young threads have the characters of

Tyndaridea, but, after a time, little swellings occur on their

sides, in which a distinct endochrome is formed, extending backwards into the parent endochrome, separated from it by a well defined

membrane, and producing, either by repeated pullulation, a compound mass like that of Calothrix, or simply giving rise to a forked

thread. In the latter case, however, there is no external swelling, but a lateral endochrome is formed, which, as it grows, makes its way through an aperture, whose sides are regularly inflected. I have

given to this curious production the name of Cladozygia Thomsoni.

The whole of the above Algae occurred at heights varying from 10,000

to 15,500 feet. As in the Southern Himalayan Algae, the specimens

were infested with many Diatomaceae, amongst which the moat

conspicuous were various Cymbellae and _Epithemiae.

The following is a list of the species observed.

Cymbella (gastroides).

-- (gracilis).

-- (Ehrenbergii)

and three others.

Odontidium (hiemale).

-- (_mesodon_). -- _n. sp._

Epithemia n. sp.

Synedra (arcus).

-- (tenuis).

-- (aequalis).

Denticula (obtusa).

Gomphonema (abbreviatum).

Meridion circulare.

There is very little identity between this list and that before given from the Southern Himalayas, as is the case also with the other

Algae. Till the species, however, have been more completely studied, a very accurate comparison cannot be made.

In both instances the species which grow in hot springs have been

reserved in order to make their comparison more easy. I shall begin in an inverse order, with those of the springs of Pugha in Tibet,

which attain a temperature of 174 degrees. Two Confervae only occur in the specimens which have been preserved, viz., an Oscillatoria

allied to that which I have called O. interrupta, and a true

Conferva extremely delicate with very long articulations,

singularly swollen at the commissures. The Diatomaceae are:--

Odontidium (hiemale).

-- (_mesodon_). -- _n. sp.,_ same as at Piti on _Conferva._

Denticula (obtusa).

Navicula.

Cymbella, three species.

Epithemia.

Scarcely any one of these except the Navicula is peculiar to the

locality. A fragment apparently of some Closterium, the only one

which I have met with in the collection, accompanies one of the

specimens.

The hot springs of Momay, (temp. 110 degrees) at 16,000 feet, produce a golden brown Caenocoleus representing a small form of _C.

cirrhosus, and a very delicate _Sphaerozyga, an Anabaina, and

Tolypothrix; and at 17,000 feet, a delicate green Conferva with long even articulations. With the latter is an Odontidium allied

to, or identical with O. turgidulum, and with the former a fine

species of Epithemia resembling in form, but not in marking, _E.

Faba, E. (Zebra) a fine _Navicula, perhaps the same with N. major

and Fragilaria (virescens).* [Mr. Thomas Brightwell finds in a

portion of the same specimen _Epithemia alpestris, Surirella

splendida, S. linearis, Smith, _Pinnularia viridis, Smith,

Navicula (lanceolata) and Himantidium (arcus).] In mud from one of the Momay springs (a), I detected Epithemia (Broomeii n.s.),

and two small Naviculae, and in the spring (c) two species of

Epithemia somewhat like E. Faba, but different from that

mentioned above.

The hot springs of Soorujkoond, of the vegetation of which very

numerous specimens have been preserved, are extremely poor in

species. In the springs themselves and on their banks, at

temperatures varying from 80 degrees to 158 degrees, at which point vegetation entirely ceases, a minute Leptothrix abounds everywhere, varying a little in the regularity of the threads in different

specimens, but scarcely presenting two species. Between 84 degrees

and 112 degrees there is an imperfect Zygnema with very long

articulations, and where the green scum passes into brown, there is sometimes an 0scillatoria, of a very minute stellate Scytonema,

probably in an imperfect state. Epithemia ocellata also contributes often to produce the tint. An Anabaina occurs at a temperature of 125 degrees, but the same species was found also in the stream from the springs where the water had become cold, as was also the case

with the Zygnema.

The Diatomaceae consisted of:--

Epithemia Broomeii, n. s.

-- thermalis, _n. sp._

Epithemia inaequalis, n. sp.

Navicula Beharensis, n. sp.

The vegetation in the three sets of springs was very different.

As regards the Confervae, taking the word in its older sense, the species in the three are quite different, and even in respect of

genera there is little identity, but amongst the Diatomaceae there is no striking difference, except in those of the Behar springs where three out of the four did not occur elsewhere. In the Pugha and Momay springs, the species were either identical with, or nearly allied to those found in neighbouring localities, where the water did not

exceed the ordinary temperature. A longer examination will doubtless detect more numerous forms, but those which appear on a first

examination are sure to give a pretty correct general notion of the vegetation. The species are certainly less numerous than I had

expected, or than might be supposed from the vegetation of those

European hot springs which have been most investigated.

In conclusion, I shall beg to add a few words on the Fungi of the

Himalayas, so far as they have at present been investigated.

As regards these there is a marked difference, as might be

anticipated from the nature of the climates between those parts of

Tibet investigated by Dr. Thomson, and the more southern regions.

The fungi found by Dr. Thomson were but few in number, and for the

most part of very ordinary forms, differing but little from the

produce of an European wood. Some, however, grow to a very large

size, as for instance, Polyporus fomentarius on poplars near

Iskardo, exceeding in dimensions anything which this species exhibits in Europe. A very fine AEcidium also infests the fir trees (Abies Smithiana), a figure of which has been given in the

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