INVERTEBRATA, CRYPTOGAMIA, MICROSCOPY, ETC. 701 



the author draws attention to the scarcity of deep-water Ciliata. To 

 get an exact idea of the Eeterotriclia found at great depths it is neces- 

 sary to see how far they are represented in the fauna of the canton. 

 The group of Heieroiricha, which is characterized by the possession, 

 in addition to short and regularly arranged cilia, of a spiral peris- 

 tomial circlet of larger and stronger, setiform, cilia, may be divided 

 into three groups— Spirostomida, Stentorida, and Bursarida. Of the 

 first family, all the species have been found in the canton, with the 

 exception of the marine genus Condylostomum ; of the second, one 

 genus, Freia, is marine, but the other, Sf enter, is rej)resented by all 

 its species ; while of the third group only two genera are free-living, 

 and of these one only has been observed, and that in the person of 

 its solo good species, Bursaria trancatella. The author states that 

 of all these forms only five have been found on the shores of the 

 lake, all of which, with the exception of B. truncatella, pass, without 

 modifications, to the bottom of the lake, where therefore Spirostomum 

 amhiguum, Stenior cceruleiis, S. poli/morplms, and S. BdselUi have now 

 been found. Of the Bhizojwda, for a long time not a single example 

 was found. A dredging off Ouchy in the winter of 1877-78 revealed 

 the presence of Amoeba princeps, A. terricola, covered with its chitinous 

 envelope, and Difflugia proteiformis, which by the production of gas in 

 its interior is enabled also to live on the surface. 



It is of interest to observe that specimens taken from the depths 

 of the lake were found to be more transparent than those from the 

 pools on the shore. 



This instalment of the results of the explorations concludes with 

 a list of the parasites and intestinal worms found in the fishes of the 

 Lake of Geneva, prepared by M. Lunel. 



" Liver" of the Invertebrata.* — M. Cadiat regards the Malpi- 

 ghian tubes of insects as belonging to the hepatic series, and points out 

 that the large cells of which their walls are made up are separated 

 from one another by spaces very similar to those which limit the 

 cells of the hepatic lobule in the Mammalia; the green colouring 

 matter which they contain exhibits with nitric acid the characteristic 

 reactions of biliverdin. The liver of the Gasteropoda is stated to 

 be broken up into lobules, which present an irregular central cavity 

 connected with intracellular passages ; the blood-vessels pass from 

 the periphery to the hepatic lobule, and the biliary ducts take their 

 origin from the central cavities of the lobules ; the secretion is deco- 

 lorized and dissolved by nitric acid and is regarded as a derivate of 

 hsematoidin in a different stage. 



Mollusca. 

 Chromatophores of the Cephalopoda.! — The play of colour in the 

 Cephalopoda was observed in the embryo, as well as in the adult, by 

 Aristotle ; later observers, such as Carus, delle Chiaje, and Wagner, 

 have shown that this phaenomenon is dependent on the possession and 

 on the movements of the so-called chromatophores or pigment spots, 



* ' CR. Soc. Biol.' for 1877 (1879), p. 217. 

 t ' SB. Akad. Wien,' Ixxviii. (1879) p. 7. 

 VOL. II. 3 A 



