Phylogeny of the Arachnida. 305 



fan-tracliefe (/. e. the lungs), as appears from the explanation 

 which he appends to the diagram of the position of the 

 stigmata in the Arachnids {loc. cit. p. 68). The ancestors of 

 tlie Arachnids possessed a pair of stigmata upon each segment 

 of the body ; as the most material proof of this fact the 

 author regards his discovery in the case of the Chernetida? of 

 rudimentary stigmata (" vestigial stigmatic scars ") upon all 

 the segments of the abdomen, commencing from the fourtii. 

 But according to Kingsley (No. 28, p. 239) the structures 

 discovered by Bernard were already known to Sieb)ld (183'J), 

 though they are not rudimentary tracheaj, but attachments 

 for the muscles upon the chitiuous envelope *. The deduc- 

 tions of this author are on all occasions too hasty. Similarly 

 I cannot say that I agree with his theory as to the develop- 

 ment of the tracheae in the Tracheata in general from the 

 bristle-glands of Worms (No. 7). But I will not stop to 

 j)ursue this further. I have previously expressed my view 

 as to the development of the trachege of Arachnids, of which 

 the stigmata are situated upon the cephalothorax, and iix 

 certain cases probably upon the abdomen also (in which cases 

 the latter occurs must be shown by future observations ; as 

 regards the former, however, I can only assume that this 

 holds good for the Pseudoscorpions, Solifugge t, Phalangidaa :|:, 

 and Cyphophthalmidai). I can now say with Korschelt and 

 Heider {loc. cit. p. 635) : — " We are consequently inclined 

 to side with those investigators who regard the Arachnids and 

 the rest of the air-breathing Arthropods as two distinct 

 series, and therefore also assume a separate origin of the 

 trachea in these two divisions." 



If now, on the basis of what I have already stated, which 

 has also appeared in my paper published in Bussian, we 

 attempt to cast a glance at the organization of the hypothetical 

 primitive type of the Arachnids {Protarachnon) , our concep- 

 tion of it must assume the following shape : — 



PkOTAEACHNON. — In the general configuration of its body 

 the animal must recall the fossil Slimonia ; the body was 

 divided into two sections, the cephalothorax and the abdomen; 

 the segments of the cephalothorax were fused together, but 



* [The author here quotes an erroneous supposition of Kingsley's, as is 

 evident from Bernard's " Vestigial Stigmata in the Arachnida," which 

 appeared in this Magazine in August 1894 (Ann. & Mag. Nat. Hist, 

 ser. 6, vol. xiv. pp. 149-153: cf. especially pp. 150-151). — Transl.] 



t The structural identity between the thoracic aud abdominal trachete 

 in Galeodes is pointed out by Bernard (No. 7, p. 521). 



+ The position of the stigmata in the Phalangidte is apparently not 

 yet precisely determined. 



