268 



As yet no tracé is to be foimd of the pattern, which appears 

 later on. The stigmata are visible as white spots. On each segment 

 there is a number of warts (in most cases ten) each of which 

 bears a simple bristle. When the small caterpillars have obtained 

 a length of 7 mm. they are olive-green and no longer form such 

 a great contrast with the green Euphorbia leaves as before ; still 

 they do not possess any definite pattern. After five days the first 

 moulting takes place and with it a very complicated pattern siid- 

 denly appears (fig. 38—39)." 



Weismann also mentions a full-grown Smerintlms (?) species 

 in the museum in Berlin of which he says, „that it is sparsely 

 covered with bristles but does not show a tracé of any pattern, and 

 agrees all the more with the youngest stage of most of the now 

 living Spingidae as it also lias short bristles thinly spread over 

 the surface of the animal. This „living fossil" had a length of 6 cM." 



For the rest the pattern of the hairs resembles that which I 

 found amongst others in Sphinx Ik/Nsfri and SnierhttJuis filiae. 



Weismann's classical treatise has rightly met with much appre- 

 ciation but, unfortunately, has found too little imitation. 



For a more exact insight into the system of the Lepidoptera a 

 complete knowledge of caterpillars will without doubt prove to be 

 of great value. 



The accuracy of Weismann's investigations and the great keen- 

 ness with which he has deducted very comprehensive theories 

 from apparently unimportant facts, guarantee to his work a pro- 

 minent place in zoological literature. 



In his next study Weismann (1876 II,) discusses the so-called 

 „parallel rows". He starts from the following argument (1. c. p. 141) : 



„If the development of the organic world depends upon a 

 phyletic vital power, there must have taken place and still be taking 

 place what T call „phyletic parallelism", i. e. the development of 

 the two stages of metamorphic species must have taken place in 

 exactly parallel direction ; each transformation of the butterfly 

 would have been accompanied or foliowed by a transformation of 

 the Caterpillar, and the systematic groups of the butterflies would 



