494 SUMMARY OF CURRENT RESEARCHES RELATING TO 



butterfly, and his study of this case of specific variation is illustrated by 

 an excellent plate. 



New Case of Protective Mimicry in a Caterpillar.*— R. Shelford 

 describes a remarkable case. On a Spirm-tikQ plant, collected at 

 Sarawak, which bore numerous pale green cymose inflorescences still in 

 bud, what looked like one of the branchlets was seen to be moving. 

 This was a small Geometer caterpillar, only 9 mm. in length, covered 

 with buds from the inflorescence on which it was feeding. Strings of 

 buds, connected by silk, were fastened to spine-like processes on the 

 body, and when the green buds faded or were removed, they were 

 immediately replaced by fresh ones. The mode of fixation is described. 

 The larva fed on the buds, scooping out the interior, and, when not 

 hurried, used empty shells in preference to whole buds for its covering. 

 When irritated, the caterpillar curled up and remained stationary for 

 15-20 minutes so that its burden of buds seemed, as the sketch shows, 

 to form part of the entourage of living buds. At other times it would 

 sway about, looking like a branchlet blown by the breeze. As is fre- 

 quently the case with specially protected insects, the species seems to be 

 rare, and the perfect insect is not yet known. 



Notes on Seasonal Dimorphism.t— F. A. Dixey, in an account of 



Lepidoptera from the White Nile, shows that in cases where the existence 

 of seasonal modification has been reasonably presumed, or even actually 

 demonstrated, the seasonal relation is far from being rigidly fixed. Thus 

 he notes (a) the persistence of dry-season coloration in the females of 

 seasonally dimorphic species ; and (6) the simultaneous occurrence of 

 diverse seasonal forms. 



Artificial Parthenogenesis in Silk Moth. J— A. Tichomiroff refers 

 to his experiments made in 1<S 8 5 which showed that very varied stimuli 

 — sulphuric acid, friction, warm water — might induce artificial partheno- 

 genesis in the eggs of the silk-moth. He has made further experiments, 

 and finds that the parthenogenetic development always shows more or 

 less abnormality. The cells of the serosa are sometimes gigantic and 

 they sometimes lie in an irregular chain in the middle of the yolk, the 

 ectoderm sometimes grows much more rapidly than the other layers, and 

 sometimes it lags behind. In short the development is not normal. 



Development of Stylopida3.§— C. T. Brues has studied three North 

 American species of Xenos, which live as internal parasites of wasps, 

 notably of Polistes. The behaviour of stylopised wasps towards their 

 parasites is usually friendly, although it is probable that the males are 

 attacked by the wasps whenever they attempt to copulate with the 

 females. Their distribution and occurrence are erratic ; due apparently 

 to the fact that as " triungulins " they do not readily become transferred 

 from one wasp to another and consequently to other nests. Large 

 numbers of larva are often found in one Polistes larva, without greatly 



* Nature, lxviii. (1903) pp. 187-8 (1 fig.). See Zoologist, May 1903. 

 t Trans. Entomol. Soc. London, 1903, pp. 141-63 (1 pi.). 



t MT. Com. f. Seidenzucht k. Moskauer Landwirt. Ges., Bd. i. Hft. 10 (1903) 

 pp 3-10 (1 pi.) (Russian). See Zool. Centralbl., x. (1903) pp. 344-5. 

 § Zool. Jahrb., xyiii. (1903) pp. 241-70 (2 pis. and 3 figs.). 



