14S PROF. W. H. JACKSON ON THE 



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

 references *. 



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

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

 in his work ' Systematische Beschreibung der Raupen unter Angabe ihrer Lebensweise 

 und Entwickelungszeiten,' Berlin, 1S61. There is a copy of this book in the Insect 

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

 In many of the plates to the second ])art sexual signs are affixed to some of the figures 

 of the chrysalids. The cremaster appears to differ in some cases in tlie two sexes, just as 

 do the antennae. On p. 4 of the Introduction, Wilde states thai the male pupa possesses 

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

 getrennte Hockerchen, wiihrend diese Stelle bei der weiblichcn Puppe geglattet, dagegen 

 abcr hinter dem Einschnitte zwischen dem 7ten und 8ten Hinge, iiber der Mitte des 

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

 ist. Die 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 

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

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

 On p. 6, Ratzeburg comjiares the segments of the pupa with the 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 Hintcrleib 10-ringlig), allein das kommt nur daher das der After sich 

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

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

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

 meine Beobachtung zufolge, miinnliche und weibliche iilierall in der Puppe untei'- 

 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 (pp 151-2), there are 

 really ten abdominal segments both in the catei-pillar and pupa alike, and that Ratzeburg 

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

 sexual apertures of pupce as described in the preceding pages. He figures in the female 

 only Vanessa ])olijchloros and the Heteroceran type 4 b with confluent apertures. In his 



*" Mr. Doncaster tells me that in the ^atjrida; the male cuterpillar is brown, the female green, and that the male 

 caterpillars of Or(/i/ia antiqua and 0. gonosligma have j-ellow dorsal brushes, the female brown. In all there are 13 

 or 14 species thus distinguished. Suckow ('Anat. Phjsiol. Untersuehiingcn,' Heidelberg, ISIS, p. 23) states that the 

 male DendroJhnns pini difi'crs from the female (1) by its smaller size, (2) by its lighter, almost smoky grey colour, 

 and ('.i) by a black-brown band, situated behind the second pair of prolcgs, which begins laterally aud takes an oblique 

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



