368 Experimental Zoology 
Quetelet found 133.5 males to 100 females; Bodio gives: — 
MALES 
Italy . 3 ; ¢ < a : : I3I.1 
France : : : : : 5 F 142.2 
Germany . j : ‘ ‘ . : 128 3 
Austria é 3 ‘ ‘ ‘ : : 132.1 
Hungary. 4 ‘ ‘ 3 . : 130.0 
Switzerland . wy ie i a Ge! Se 135.0 } to 100 females 
Belgium 5 ‘ ‘ 3 ‘ : : 132.0 
Holland . ‘ : . : ; ‘ 127.1 
Sweden . 3 : ; : ; ; 135.0 
Norway ‘ : ‘ 3 : : ‘ 124.6 
Denmark. : : b) #3 . : 132.0 
From these results it is clear that the proportion of male to 
female embryos is distinctly in favor of the males. The mean- 
ing of this is unknown. 
Monecious Species, composed of Bisexual or Hermaphrodite 
Individuals 
Since the groups of animals with which we are most familiar, 
the vertebrates, insects, and higher crustaceans, are composed 
of individuals with separate sexes, we are apt to forget how often 
in other groups the sexes, or more accurately the sex-cells, are 
united in the same individual. In the following list some 
of the groups are given in which hermaphrodite individuals 
exist : — 
Sponges, sexes separate or united. 
Ccelenterates, sexes separate or united. 
Flatworms, sexes united, a few cases of separate sexes, 
Nemerteans, sexes rarely united. Separate sexes the rule. 
Nematodes, sexes separate as a rule, but united in some cases. 
Annelids, sexes united in earthworms, separate in marine worms (except 
Protodrilus). 
Crustacea, sexes separate, but united in some barnacles. 
Mollusca, sexes separate in some, united in other groups. 
Echinoderms, sexes separate, united in a few cases. 
Thus in the greater number of the great groups, hermaphro- 
