200 THE entomologist's recokd. 



volume of The Natural History of tJw British Lepidoptera, p. 446, the 

 view that the luodification of the sexual organs themselves is 

 the cause of all the peculiarities of the secondary sexual structures — 

 antennaB, wing-colour, wing-shape, &c. Popularly, specimens that 

 present a combination of the external secondary sexual characters, are 

 termed gynandromorphous, but the actual experiments in Avhich it has 

 been proved that the modification of the secondary sexual characters 

 have been really accompanied by the modification of the primary 

 sexual organs are very few indeed, and gynandromorphism is, as a rule, 

 applied to all individuals that exhibit a combination of the secondary 

 characters recognised as belonging to difierent sexes, without the 

 slightest real knowledge that the primary sexual organs have under- 

 gone any modification, much less whether such modification is really 

 the motive force that has developed the secondary sexual peculiarities 

 exhibited. 



A superficial examination of many specimens, however, leads one 

 to suppose that such is the case, and that the modification of the 

 sexual organs in the slightest degree brings about, as we have just 

 stated, a corresponding diflt'erence in the secondary structures, and that 

 the mixed characters shown even by the same wing in some very 

 aberrant examples, are due to the development of certain male genera- 

 tive structures among those of the female (or rice versa), and it may be 

 that the development of testicles on one side of an insect and ovaries 

 on the other, results in those perfectly symmetrical specimens which show 

 antennfe, wings, legs, &c., with male characters on the one side and 

 female characters on the other. At any rate it is quite certain that 

 the external parts of the sexual organs follow a modification parallel 

 to those of the secondary sexual organs in many such specimens. 



It would be exceedingly interesting if all those le])idopterists who 

 possess specimens that show modification in the direction here 

 indicated — either as to antennae, legs, or wings, where these difi'er in 

 a species as secondary sexual characters — would record such. One is 

 convinced that there are many specimens in our cabinets showing 

 externally greater or less signs of gynandromorphism, which have not 

 been detected owing to the partial and piecemeal and sometimes 

 apparently insignificant nature of the structures involved. 



One important feature of Dr. Wood's paper, however, is his 

 attempt to show by Avhat means or through what channel the close 

 relationship Ijetween the primary and secondary organs is efi'ected. 

 He states that until recently no other explanation was possible except 

 the one that it was due to the agency of the nervous system, some 

 stimulus or impression being conveyed from the reproductive glands 

 to that part of the nervous system presiding over the development cf 

 any particular secondary character, in consequence of which the latter 

 takes on its proper growth and form. He considers, however, that 

 the comparatively modern discovery that the glands of the body, 

 besides the functions of producing their ordinary secretions which find 

 their way into the duels, have also the power to produce what may be 

 teimed " internal " secretions, Avhich pass back into the blocd, Avhere 

 they probably act as highly speciahsed foods necessary to ihewell-beingof 

 the organism, helps i";s, and it is in this direction that he would explain 

 the phenomena presented by the relationship known to exist between 

 the primary and sexual organs, and instead of the "nerve-bond" 



