148 PEOF. W. H. JACKSON ON THE 



want of time has prevented my searching its pages so as to point out the proper 

 references *. 



Addendum. — Since this paper was read I have found that the anatomical sexual 

 distinctions of chrysalids were known in part to O. Wilde, and are briefly mentioned 

 in his work ' Systematische Beschreibung der Eaupen unter Angahe ihrer Lehensweise 

 und Entwickelungszeiten,' Berlin, 1861. There is a copy of this book in the Insect 

 Boom at the Natural History Museum, where it was shown me by my friend Mr. Heron. 

 In many of the plates to the second part sexual signs are affixed to some of the figures 

 of tbe chrysalids. The cremaster appears to differ in some cases in the two sexes, just as i;v 

 do the antennge. On p. 4 of the Introduction, Wilde states that the male pupa possesses 

 " in der Mitte der Bauchflache des letzten Hinges zvvei kleinere, durch eine Langsfurche \ 

 getrennte Hockerchen, wahrend diese Stelle bei der weiblichen Puppe geglattet, dagegen 

 aber hinter dem Einschnitte zwischen dem 7ten und 8ten Binge, iiber der Mitte des 

 letzteren, eine seichte, mehr oder weniger deutliche, kiirze Langsfurche wahrnehmbar 

 ist. Hie Unterscheide entspreche der verschiedenen Lage der Eortpflanzungsorgane bei 

 den beiden Geschlechtern." Wilde appears to have been acquainted with only one type 

 of the Heterocera, at least in the female, viz., the one with confluent apertures. A 

 comparison with the foregoing account will show that there is a greater variety in the 

 sexual marks than he supposes, and that he has not placed them with complete accuracy, 

 owing probably to his not knowing the true number of segments in the abdomen. , 



A second authority has noticed the sexual apertures of chrysalids. Dr. Haase of 3 

 Konigsberg has been good enough to draw my attention to J. T. Ch. Batzeburg's work 

 'Die Eorst-Insecten,' Th. ii. (Berlin, 1840), and to give me a reference to its pages. 

 On p. 6, Batzeburg compares the segments of the pupa with tbe segments of the 

 caterpillar, to which he assigns, by the way, 9 abdominal segments (p. 4). Speaking of 

 the last three larval segments, he says, " Letzere scheinen in der Puppe zwar 4 zu sein 

 (also der ganze Hinterleib 10-riuglig), allein das kommt nur daher das der After sich 

 besonders abschnurte. Dicht vor der Afterspalte liegt die Geschlechtspalte. Bei der 

 mannlichen Puppe setz sie sich aber bis in den vorletzten Bing fort, wahrend sie bei 

 den weiblichen auf der letzten beschrankt ist (z. B. T. xii. E. 3, 4, p.). So kann also, 

 meine Beobachtung zufolge, mannliche und weibliche iiberall in der Puppe unter- 

 scheiden (s. d. zahlreichen Abbildungen)." With reference to this passage I may 

 remark that, as stated later on in the second part of my paper (ppi 151-2), there are 

 really ten abdominal segments both in the caterpillar and pupa alike, and that Batzeburg 

 (like his successor in time, Wilde) was not acquainted with the detailed variations of the 

 sexual apertures of pupae as described in the precediug pages. He figures in the female 

 only Vanessa poly chlor os and the Heteroceran type 4 b with confluent apertures. In his 



• Mr. Doncaster tells me that in the Sotyridoc the male caterpillar is brown, the female green, and that the male 

 caterpillars of Orgyia antiqua and 0. gonostigma have yellow dorsal brushes, the female brown. In all there are 13 

 or 14 species thus distinguished. Suekow (' Anat. Physiol. Untersuchungen,' Heidelberg, 1818, p. 23) states that the 

 male Dendrolimus pini differs from the female (1) by its smaller size, (2) by its lighter, almost smoky grey colour, 

 and (3) by a black -brown band, situated behind the second pair of prolegs, which begins laterally and takes an oblique 

 dorsal course. This band is obscurely marked in the female. 



