﻿60 DEBY'S RESEARCHES ON THE CRYPTOGAMIC FLORA 



midomonas and to Gleococcus, and, if I mistake not, one of its forms is identical with 

 the Diselmis viridis, described by Dujardin in his Natural History of Infusoria, as an 

 animal. Kiitzing mentions this species in his work entitled " Ueber die Verwandlung 

 der Infusorien in neideren Algenformen (Nordhausen, 1844)," and gives it as an 

 example of the impossibility that exists of separating distinctly the animal from the 

 vegetable kingdoms. Von Flotow (in Nova Acta Academ. Naturae curiosus, Vol. 

 xx., p. 11, 1844,) has given a long account of it, but his work contains many errors 

 of observation and of induction. Alex. Braun (Betrachtungen iiber die Erscheinung 

 der Verjiingung in der Natur. Leipzig, 1851,) has, in divers portions of his book, 

 given, in a fragmentary form, by far the most elaborate treatise on Chlamidococcus 

 with which we are acquainted. His observations are most accurate and interesting.* 



I have been happy enough to fill up some gaps in the history of this minute am- 

 phibolical plant, and shall give as complete an account of this species of Alga as it is 

 in my power. 



Chlamidococcus is found, in dry weather, forming a dirty, brownish or reddish tena- 

 ceous crust, spread in the small hollows of rocks ; it may be scraped off with a knife. 

 If put into water it very soon softens, and we find it to be formed of a number of 

 simple round cells. These cells are all of one kind ; their diameter varies from l-10th 

 to 1-36 th of a millimetre, their outer membrane is thick, their contents finely granular, 

 and of a reddish color, nearly opaque. Inside we find from two to six grains of 

 amylon (fecula) whose diameter does not exceed the l-120th of a millimetre, as a max- 

 imum, and which were first recognised as such by Alex. Braun, who says that he has 

 discerned in their centre a speck (nucleolus) which turns reddish by the application 

 of the tincture of iodine, whereas the remainder of the amylon grain takes the charac- 

 teristic tint of fecula. This would indicate a proteine substance in a thick coating of 

 amylon. 



In the middle of the cell, (but very difficult of observation, on account of its opa- 

 city) is found a large, delicate cytoblast. Fig. 1. 



All the round cells above described are, by the ordinary tests, found to be formed, 

 like nearly all other cells, by two coatings : an exterior one of gelinf and an interior 



[* I regret not having been able to consult Prof. Morren's Physiological Researches on the Belgian Hydro- 

 phytes, niunely, his fifth memoir on the History of the Genus Haematococcus of Agardh, not having been able 

 to procure this work. 



t Several kinds of cellular membrane are usually confounded under the name of cellulose : I recognise as 

 these principle forms : 1st. The arnyl cell membrane, which turns blue by the simple application of tincture of 

 iodine. 2nd. The gelin cell membrane, which only turns blue by the combined action of sulphuric acid and the 

 tincture of iodine. 3d. The bassorin cell membrane, which takes a brown or yellow coloring by the preceding 

 tests. 4th. '1 he protein cell membrane, which takes a rich orange tint by the tincture of iodine, but can be 

 distinguished from the bassorin cell membrane by its behaviour when treated with hot nitric acid. The three 

 first of these seem to be identical in chemical composition, having for formula C 12 H 20 O 10 , or what is the same 



