308 J- Beard 



For, as a matter of fact, I feel no direct conceru with any of those 

 species of the genus, regarding which I am unable to criticise 

 Wheeler's results from my own work, from that of others, or be- 

 cause of assumptions of bis, wbose justifieation can be challenged. 

 Thus, I bave notbing to say concerning M. cirriferum beyond ac- 

 cepted matters of fact. I feel under no Obligation to investigate 

 this form, for, as Prouho sbrewdly observes, tbere exists no reason 

 a priori for supposing that what obtains for one species of tbe genus 

 will hold for all. Wheeler, it may be observed, appears to over- 

 look one ditference in tbe life-history of M. cirriferum and that of 

 M. glahrum^ tbat in the former what he believes to be tbe young 

 forms are never dorsicolous like certain small ones in the latterà. 



Wheeler's arguments regarding tbe subsequent hermapbrodite 

 nature of tbe originally male dorsicolous forms in M. glabrum depend 

 primarily on two premisses. 



These are 1) tbe passage or migration of tbe dorsicolous forms, 

 at a certain pbase, from tbe back of tbe hermapbrodite to tbe disc; 

 2) tbe ovarian nature of Nansen's organs. 



One seeks in vain for direct proof of tbe first in bis memoir. 

 It is merely inferred, and from tbe following. Wheeler describes 

 in all ten specimens of M. glabrum^ ranging in size from 0.175 mm 

 to 4 mm. 



Of tbese six are dorsicolous, i. c, what I bave termed males, 

 while four are from tbe disc. The transformation takes place, ac- 

 cording to hira, when tbe animai is about 1 mm long. From tbe 

 largest of tbe dorsicolous forms he figures in fig. 56 what is ap- 

 parently an Qg^^ lyiog on one of tbe >ovaries«. From my own ex- 

 amination of dorsicolous specimens it can only be stated that search 

 has been long and laboriously made for any such appearance. 

 One swallow does not make a summer, and the picture of one 

 Q^^^ even if tbere be no mistake as to tbe dorsicolous nature of tbe 

 form, from which it was taken, does not make an hermapbrodite. 



Wheeler's conclusion of tbe transformation of tbe dorsicolous 

 form into tbe hermapbrodite is tben a pure inference, and it is now 

 necessary to examine the grounds, upon which he has been led to 

 make it. In tbe first place, and above all eise, comes the evidence 



1 It is true, that Semper described one such case, biit as this has not 

 been confirmed by anyone eise, and not by Wheeler, it is very probable that 

 by a slip of the pen Semper wrote cirriferum for glubruni. 



