308 DAVID BRYCE ON 



fitted him for sucli an investigation. In the course of his re- 

 searches he found rotifers both among mosses and in the lakes 

 and ponds. In the former situation they were relatively 

 scarce, while in the lakes they were extremely abundant in 

 individuals, though the number of different species was 

 comparatively small. From the mosses he was only able 

 to obtain two species (one previously unknown), and from 

 ponds and lakes only 14 species (including 4 new forms). 

 I may point out that of these 14 species found in lakes, no less 

 than 5 are species which are known in this country, but are 

 never, or rarely, found in such habitats, while common enough in 

 mosses. As these 5 species were not found in the Antarctic 

 mosses, it may be inferred that the conditions of life in the lakes 

 were more endurable than in the mosses ; so much so that 

 these 5 species have abandoned their customary habitat and 

 adopted another of quite a different character, and that not 

 sporadically, but en masse. A second instance of temperature 

 or climatic influence upon the Antarctic Rotifera can be noted. 

 Of the five species described by Murray as new to science, two 

 without any doubt belong to Bdelloid genera whose other mem- 

 bers, so far as yet known, are without exception oviparous. 

 These two species, Adineta grandis Murray and PhUodina gre- 

 garia Murray, are, on the contrary, viviparous. While other 

 species of the same genera in the same habitat have retained the 

 oviparous method of reproduction, these two species alone show 

 this startling divergence from all known relatives of their 

 respective genera. 



The Antarctic list of 16 species of Rotifera resulting from 

 the researches of such an experienced biologist as Murray, carried 

 on for more than a year, compares very poorly with the Spits- 

 bergen list of 81 species, of which 51 were obtained from a few 

 mosses selected by non-expert hands. Two explanations may 

 be suggested for the disparity, each perhaps partly responsible. 

 Firstly, the extreme severity of the conditions of life near Cape 

 Royds, which only a few species have succeeded in enduring. 

 Secondly, the greater accessibility of Spitsbergen — its nearer 

 proximity to countries affected by the beneficent Gulf Stream. 

 I would add that moss- dwelling rotifers with their very excep- 

 tional powers of retaining vitality while apparently dust-dry, 

 and with eggs of even greater endurance than the adult animal, 



