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THE AMERICAN NATURALIST [Vol.XLVI 



most peculiar feature which I have found in the species. 

 They plainly do not agree with Eousselet's characteriza- 

 tion of the egg of A. amphora: 11 The outer shell en- 

 velope consists of numerous much smaller globular trans- 

 parent cells" (smaller than the cells in egg coat of A. 

 brightwelli) " through which a finely dotted inner mem- 

 brane can be seen." I find that at a certain intermediate 

 stage of development a dotted inner membrane can be 

 seen, the dots being the ends of either tubes or 

 rods making up a thick inner coat; the rapidly devel- 

 oping outer shell, however, soon obscures these dots and 

 the coat assumes at first a wrinkled, then a heavily cor- 

 rugated, surface. The corrugations are so disposed that 

 many of them converge at two opposite poles of the egg. 

 I deem it quite impossible that this characteristic and 

 beautiful structure should have been overlooked by any 

 one studying this species in detail and with the full char- 

 acters which it possesses in the writer's vicinity. It 

 therefore seems very probable that the type of A. am- 

 phora studied by Kousselet was not identical with that 

 studied by the writer, and it may accordingly prove 

 necessary to eventually separate the form I have 

 studied from the original type of the species, ascribing 

 it varietal rank, based on at least this one character of 

 the egg coats. The systematic predicament in which 

 this would place these beautiful rotifers would indeed be 

 pathetic or intolerable or humorous, according to our 

 attitude toward things systematic. We should have two 

 varieties, separated from each other by a single fixed 

 character only, and one of these varieties would comprise 

 within itself, besides a host of minor variations, three dis- 

 tinct types, each of which differs from its fellow, not only 

 more than do the varieties differ from each other, but 

 more than the whole species, at its nearest point of ap- 

 proach, differs from its closest congeners. 



There is not the least known reason why actual facts 

 of genetic relationship should not be as complicated as 

 this, and if they are so we must deal with them systemat- 



