206 THE PHENOMENON OF 



Normal fully-developed cells of this multiform creature, 

 sometimes like a plant, sometimes like an animal, present 

 the appearance of globules, from ^th to ^th millim. in 

 diameter, with a thick tough cell-membrane, and 

 granular-punctate, opaque contents, sometimes of brown, 

 sometimes (at other periods or in other localities) bright 

 red colour. In the mass of the dark contents lie hidden 

 several other structures, which at this period are com- 

 pletely concealed, namely 4 6 starch-globules, of ^th, 

 or at most ^th millim. in diameter, in which, as in those 

 of Hydrodictyon, a nucleus and an envelope may be 

 distinguished, acquiring a dirty violet colour with iodine, 

 the nucleus becoming rather redder. Sulphuric acid 

 causes a considerable swelling up of the coat. There 

 also appears to exist in the centre of the cell a large, 

 very delicate nuclear vesicle, which, however, is so 

 covered up by the rest of the cell-contents, that it can 

 only be very indistinctly perceived, and cannot even be 

 clearly displayed when the contents are squeezed out. 

 When these resting globular cells are placed in water, 

 they give birth, in the way already described (p. 184), 

 to four gonidium-like swarming cells. Even before the 



persons, I venture to draw attention to the very wide diffusion of this 

 species. Von Flotow, the discoverer of Chlamidococcus pluvialis, found 

 it, in the year 1841, in a shallow hollow in a granite slab forming the 

 foot-bridge across the Frosch-graben, near Hirschberg; subsequently (184-6) 

 also in excavations in the granite rocks of Opitzberg, near Hirscliberg, 

 where the raiu-water collected. Dr. Mettenius found it recently, also, in 

 cavites of granite rocks, at Harlass, near Heidelberg. I found it for the 

 first time in shallow hollows of horizontal sandstone slabs, on the walls 

 of several bridges near Freiburg, in February, 1848, accompanied every- 

 where by a beautiful Rotifer (Philodina rosed), and in one shady spot 

 associated with Mastichonema pluviale. The pastor Brunner found it last 

 winter in the district of Donaueschingen, in several churchyards, in the 

 basins cut to hold holy water of the (sandstone) gravestones, and also in 

 the iron vessels fixed on the tombs for the same purpose. I found it at 

 Neuenberg, in Switzerland, in the years 1844 and 1S48, in the hollows 

 formed by ancient denudations of the calcareous rocks bordering the lake, 

 and in this place of especially bright red colour. Kiitzing indicates it also 

 from Bohemia (according to Corda), France (Brebissou), and Scotland 

 (Greville), as he regards H&matococcus Corda;, Meneghini, and Protococcus 

 nivalis, Grev., (Scott, ' Crypt. Flora,' t. 231,) as the same plant as Hcemato- 

 coccus pluvialis, V. Flotow, on which point 1 do riot yet venture an opinion. 



