43 



Cramer, ///. 138 //. 187 ^, /^ (1779) Pap. Jugurtha. 



////. 63 //. 229 D, E. (1782) , Catilla. 



IV p. ^^ pi. 339 A, B. (1782) Hilaria. 



BoiSDUVAL, Spec. Gen. //. 625 (1836) Callidryas Crocale. 



„ „ „ 627 (1836) „ Alcmeone. 



Snell. v. Voll. Mon. d. Pidr. /. 60 (1865). . . . Catopsilia Hilaria. 



„ 61 (1865). ... „ Alcmeone. 



Distant, Rkop. Mai. p. 296//. 25^?^. 11, 12.(1882 — 86) „ Crocale. 



., „ 297 „ 25 „ 15, 16. (1882 — 86) „ Catilla. 



Staud., Exot. Schm. p. 39 //. 22 (1884 — 88). ... „ Pomona. 



Bingham, Fauna of Br. India p. 219 (1907) .... „ Crocale. 



It is not necessary to mention the places where I caught this butterfly for 

 it is equally common in all parts of Java ; and so it is in many regions of the 

 Indo-Australian territory. It is even doubtful whether any forms that occur in 

 Africa and America, really differ from it specifically. It is this species which 

 forms in Java the great flights of apparently travelling butterflies, which are so 

 often seen there; according to Dr. Martin this is also the case in Sumatra. 

 Repeatedly have I been able to observe these so-called migrations, which may 

 often be seen on sunny days, principally in November and December, but also 

 in the following months of the rainy season, especially when the preceeding 

 dry season has been particularly dry. In two essays I have published the 

 results of these observations and the considerations to which I came by com- 

 paring these with numerous other ones, made elsewhere, especially in Europe. 

 Both have appeared in the French language in the Natuurhmdig Tijdschrifi 

 voor Nederlandsch Indie. The first entitled: Observations stir des vols de Lipi- 

 dopteres aux Indes Orientales Neerlandaises et cons idd rations sur la nature probable 

 de ce phenomene, in the 50* volume (1890), and the second, entitled: Nouvelles 

 observations sur les vols des Lcpidopteres in the 57''' volume (1897). Without 

 hesitation I dare say that these two essays contain the most complete study 

 about this subject that exists. It seems to me that I. W. Tutt has not assigned 

 the required value to them in his work : " The Migration and Dispersal of Insects ", 

 published in 1902. The author evidently knows only the former of these essays 

 and has taken the liberty to borrow from it several facts without mentioning 

 the source ; he does not know the second, however, and neither f. i. the inter- 

 esting essay: "Insektenreisen" by Prof. Karl Sajo, published in the " Illustrierte 

 Wochenschfift fur Entomologie" of the year 1897, though his work pretends to 

 be complete. His work has but a compilatory value ; the insignificance of his 

 XIX'*' Chapter alone, entitled: "Final Considerations" already shows us clearly 



