366 MONTGOMERY — MORPHOLOGICAL SUPERIORITY. [Oct. 7, 



The object of the present contribution is to deal with the subject 

 briefly from the anatomical and embryological standpoint ; consid- 

 ering first the Invertebrates, and lastly the Vertebrates. 



I. The Invertebrate Animals. 



Lamarck's collective group of the ^^ Invertebrata " is of course 

 retained to-day only for convenience; the numerous phyla which 

 compose it differ far more greatly from each other than do any of 

 the extremes of the Vertebrata. 



In the Invertebrata, whenever there are marked structural differ- 

 ences between the sexes, it will be found to be a rule almost with- 

 out exceptions that the male is morphologically inferior. 



There are, in the first place, those numerous cases where the sexes 

 are markedly different, in that one is much less developed than the 

 other, i.e., is the resultant of much shorter embryonic growth. 

 Thus all the families of the Rotatoria so far as known, with the 

 exception of the Asplanchnidae ^wd Seisonidae, possess males inferior 

 to the females in much smaller size and complete absence of the 

 digestive system. As I expressed myself in a study of the Floscu- 

 lariidce, these males are arretted individuals. A more marked 

 example is found in the Echiurid Bonelliay where the male is 

 only one one-hundred-and-fiftieth the length of the female, and 

 lacks an anal aperature ; he is a degenerate, living as a parasite 

 within the female. Similar examples occur in the Cirripedia. 

 On the other hand it is seldom found that the female is embryo- 

 logically more arrested than the male ; such a case is that of the 

 glowworm, however, where the male is winged but the female apter- 

 ous, and in certain Hemipteta heteroptera. But these are arrests in 

 external organs of locomotion, implicating less profound changes 

 than those shown in the preceding cases. 



Our case holds even for most hermaphrodites, paradoxical though 

 it may at first appear to speak of males and females among herma- 

 phrodites. In almost all examples of hermaphroditism it is the rule 

 that the male and female organs of generation and reproductive 

 cells do not mature simultaneously, but successively, as I have 

 shown elsewhere.* In the greater number of these cases the male 

 germ cells mature and are discharged first, then the female, a con- 

 dition known as protandry. Here the individual is functionally 



1 •* On Successive, Protandric and Proterogynic Hermaphroditism," Amer. 

 Nat., 1895. 



