A CRITICAL STUDY OF AMORPHA POPULI, LINN. 61 



in tint to that of the middle area of the forewings, with a slightly 

 darker apex, and show only a slightly rusty-coloured base. The fore- 

 wings have no discoidal lunule nor the bright apical mark. I do not 

 think it wise to publish any conclusion on this specimen, as I have 

 only seen the photograph and do not know the original at all. 



For this reason it is impossible for me to enter into a more detailed 

 comparison of Koch's type with Glaser's described specimens, and it is 

 not, therefore, yet confirmed that Glaser changed his diagnosis, in Nenen 

 Borkhausen (1863), in order to make it agree with Koch's picture. 

 I, therefore, shall not be able to decide this point until I have compared 

 Glaser's types of 1863 and 1863 with Koch's type. It is a pity that 

 there is nobody now in Biedenkopf who could undertake this and give 

 a final decision on the point. 



In his Schiietterlinge Deutschlands, 1865, p. 95, Dr. Holle proposed 

 two names for a new variety of A. popidi, (1) in consideration of the 

 foodplant of the caterpillar, and (2) the habitat of the moth. In 

 the first case, the moth he said, might be called salicis (the caterpillar 

 only living on willows), in the second case it could be called pahistris 

 (the caterpillar and moth occurring on "mosses.") The caterpillar is said 

 to be similar in its habits to that of Siiierinthns ocellata, holding its 

 head slopingly upwards and sheltered by the prolegs. The moth is 

 said to have, however, only shaded markings of the transverse lines of 

 A. popiili and bears the same relation to the latter as Gastrojmcha 

 popnlifolia, Esp., bears to G. quercifolia, Linn., also the same relation as 

 to size. The red colour of the hindwings is said to be missing. 



The transverse lines may disappear altogether or partly, in Amorpha 

 populi, Linn., as I have shown already in hisekten-Borse, xix., 1902, pp. 

 228-229, for ab. tremulae, Borkh., and also in Allcjem. Zeitsrhr. fur 

 Entomolof/ie, vii., 1902, pp. 375-878, for ab. subjiara, Gillmer, but 

 this is seldom the case. The colour of G. popuUfolia is yellow-brown, 

 whilst the colour of G. quercifolia is copper-brown with a violet gloss. 

 The size of the two is about the same. Judging from von Heinemann 

 {Schmett. Deutschlands, i., 1859, p. 203) the length of the forewing from 

 the base to the apex varies in G. populifolia from 27mm. to 31-6mm., 

 in G. quercifolia from 24'8mm. to 38-4mm., so that populifolia, contra- 

 dicting the opinion of Dr. Speiser, on an average, is not quite the size 

 of quercifolia. On p. 117 of his book. Dr. Holle asserts that populifolia 

 is larger than quercifolia, but this is not the case with his A. populi, 

 or otherwise the typical moth p)opuli must have been very small at 

 this time in Hamburg, which does not agree with my later observa- 

 tions. Concerning the entire disappearance of the red basal blotch of 

 the hindwings in A. populi, I have already remarked that such 

 specimens have not yet been recorded. The basal blotch often appears 

 of a pale colour and reduced, yet it is an exaggeration to write that it 

 is missing entirely. Neither is this assertion borne out by the six 

 specimens of A. populi which I possess from Holle's collection. Most 

 probably Holle has gone too far in favour of Esper's variety of olden 

 times, and would like to have secured the recognition of his 

 variety as a distinct species, as was the case with Borkhausen over 

 tremulae. Therefore, he gives biological data similar to those of 

 Borkhausen, but, as a separate species, Holle's form must meet the 

 same end as did tremulae, Borkh., at the hands of Ochsenheimer 

 (1808). 



