43 



and wait for the next thaw. This may not come for years in 

 those deeper lakes which do not melt in ordinary summers. But 

 "even in one of these, under fifteen feet of ice, rotifers were 

 numerous. It was found experimentally that these organisms are 

 able to withstand greater heating and greater cooling than they 

 ever experience naturally. It is especially noteworthy, as bearing 

 on their dispersal over the region, that they were not killed by 

 sea-water, nor by a much more saline fluid found in some small 

 lakes. 



Mr. W. Wesche, F.R.M.S., said he would like to ask the 

 lecturer whether he could do anything to clear up the vexed 

 question of the males of bdelloid rotifers. Then, again, in the 

 viviparous forms, are the young born one after the other or all at 

 one time ? It was very interesting to watch, say, R. vulgaris in 

 a compressor, and see the young ones shoot out and begin life on 

 their own account. Were other rotifers besides bdelloids experi- 

 mented on as regards temperature-resisting ability ? 



Mr. Murray, replying, said that no male bdelloid had been 

 found. As regards the viviparous habit, he had but rarely 

 observed this. He thought that when a compressor was used, 

 it introduced conditions certainly not natui-al. The experiments 

 had been confined to bdelloids. 



Mr. J. Burton, referring to the specimen of undetermined 

 vegetation exhibited, suggested that it might be a symbiotic 

 union between a fungus and an alga, practically amounting to 

 a lichen. It might be that a symbiotic union between such 

 organisms would enable them to live under conditions neither 

 of them could endure apart. He noted that the material shown 

 split into small laminae. Was it likely that each sheet 

 represented one year's growth ? 



Mr. D. Bryce said that perhaps the most remarkable point 

 mentioned by Murray with regard to Antarctic Eotifera was the 

 occurrence of two viviparous species belonging to Bdelloid genera, 

 which, so far as they are yet known, are always oviparous in 

 places where such extreme cold has not to be experienced, and it 

 was particularly noteworthy that in these two species the embryos 

 seemed to be matured in batches, not successively. It is a 

 general rule among bdelloids that the two ovaries alternately 

 produce ripe eggs. In R. vulgaris the female may be observed 

 to contain a number of embryos of different stages of growth. 



