PRIMARY AND SECONDARY SEXUAL CHARACTERS IN LEPIDOPTERA. 199 
The connection between Primary and Secondary Sexual Characters 
in Lepidoptera. 
By J. W. TUTT, F.B.S. 
Not the least interesting of the various pots discussed in Dr. 
Wood's recent paper on certain Lithocolletids (Int. Mo. May.) is the 
final chapter on the biological aspects of the male genitalia. The 
working theory advanced is certainly far-reaching in its application, 
and one suspects that some first class entomologist will ere long put it 
to the test of practical application. 
One is, indeed, astonished that there should be the remarkable 
variety which Dr. Wood shows to exist in the structure of these 
organs among such small insects, and that closely allied species 
should present such wide differences is also sutticiently striking, and 
one is inchned to agree with the author that this variation is not 
solely to prevent unnatural unions. It is not, however, this particular 
view of the subject to which we wish to refer, but rather to a side 
issue growing out of one of the pomts raised by Dr. Wood. 
Dr. Wood concludes that « much of the variation that we find in 
the male appendages is of a neutral character, neither useful nor hurt- 
ful to them as clasping o organs.’ . . . and that “all this amazing 
fertility of shape is dependent in some way upon the presence of the 
reproductive glands or testes, for it can scarcely be doubted that could 
they be removed at a sufficiently early date in the life of the larva, 
the transformation of the last larval segment into the armature of the 
imago would not occur, much as the emasculation of the deer prevents 
the development of its horns.” He then goes on to suggest ve the 
office of the reproductive glands (testes or ovaries) is twofold: (1) The 
production of spermatozoa or ova. (2) The control of the development 
of the soma. ‘These two functions are rarely in full activity at the 
same time . . . . and the organs may be capable of discharging 
one set of functions and incapable as regards the other. He says: 
‘The functions then of the reproductive glands are twofold; on the 
one hand they supply germ-matter that resides within them with the 
means of developing and multiplying ; and, on the other hand, they 
modify and even originate those parts of the soma which are lumped 
together under the name of the secondary sexual characters. Now, 
the more minutely we investigate and classify ow: insects the more 
commonly do we come upon instances in vee the only coarse and 
tangible characters by which one species may be distinguished with 
certainty from another closely allied to it, lie in these secondary sexual 
structures; in fact the structures constitute for us the specific 
characters. Hence the conclusion seems inevitable, that many of the 
characters that go to form a species have their start in some primary 
change in the reproductive glands and that these organs are not 
merely passive agents concerned in the nourishment of the germ-matter, 
but do themsely es take an active and creative part in the genesis of 
species.” 
Since | have been studying the Lachneids (Lasiocampids) 1 have 
been brought face to face with the necessity of forming some sort of 
ppinicn as to the cause of the external peculiarities of gynandro- 
morphism, and some time since T came to the conclusions that Dr. 
Wood has so ably formnlated. LT have already steted, m the second 
