226 THE entomologist's record. 



the mammalia, where one tj'pe of sex gland is present, but where the 

 other portions of the secondary sexual apparatus are intermediate in 

 character and most closely resemble those of the sex opposite to that 

 to which they actually belong. This condition is made possible by 

 the fact that these portions of the secondary sexual apparatus are 

 absolutely homologous in the two sexes. Such pseudo-hermaphrodites 

 are bilaterally symmetrical, whereas as3a'nraetry is the most noticeable 

 feature of these abnormal coridnn. 



I venture to suggest the following classification of these different 

 forms of hermaphroditism. 



(1) Genetic heriiiaphroditis)ii. This is to be confined to those cases 

 in which germplasm of both sexes is present, i.e., both ovarian and 

 testicular tissue. A number of gynandroniorphs belong to this class. 



(2) Primary Souiatic lieriiiaphroditisiii. In this class germplasm 

 of only one sex is present (ovary or testis), but secondary sexual organs 

 of both sexes. The secondary sexual organs are formed of somatoplasm. 

 Some gynandromorphs belong to this class. 



(3) Secoiidari/ Somatic heniiaidiroditis'ii. In this class both sex 

 gland (germplasm) and secondary sexual organs (somatoplasm) belong 

 to one sex, but secondary sexual characters of both sexes are present 

 in the wings and other parts formed of somatoplasm. To this class 

 belong the Royston coridnn (nos. 1 to 6) and probably all similar 

 specimens. 



The name gynandromorph is comprehensive, and merely means 

 that both male and female characters in wing markings or coloration 

 are present, and covers both groups. Unfortunately most of our 

 gynandromorphous specimens are never dissected, and we do not know 

 whether they are true hermaphrodites or not. All those which have 

 been dissected have proved to be so, but they only form a small pro- 

 portion of the total number. 



Sex appears to behave as a Mendelian character, the female being 

 heterozygous and the male homozygous. A possible explanation of 

 hermaphroditism is that it is due to an abnormal division of chromo- 

 somes. One nucleus obtains too much of the chromatin substance 

 which determines maleness or femaleness, and one too little. The 

 recessive is able to show its presence either completely or partially, 

 according to the complete or partial absence of the chromatin substance, 

 which should have prevented it from showing its presence. More 

 probably it is due to the fertilisation of an ovum with two nuclei by 

 two spermatozoa. This occurrence, which has been proved to occur, 

 would explain the presence of two complete sets of genital apparatus, 

 internal and external, in some gynandromorphs. The presence of a 

 doable external apparatus in an individual developed from a single ovum 

 and spermatozoon would be impossible if the external structures in 

 the two sexes are homologous. There are difficulties in the way of 

 accepting this theory, but they do not appear insurmountable. 



Hermaphrodites in the lepidoptera show a series running from 

 those in which the primary and secondary sexual characters of both 

 sexes are evenly balanced, to those in which the characters of one or 

 other sex preponderate to lesser or greater extent, liut the primary 

 sexual characters of both sexes may be evenly balanced, whilst the 

 secondary sexual characters of one or other sex greatly preponderate, 

 and vice versa. For instance, the secondary sexual characters of the 



