ZOOLOGY AND BOTANY, MICEOSCOPY, ETC. 423 



abundance in the perivisceral fluid of the Coccid Kermes quercus. It 

 is probably one of the Saccharomycetes. Another species, K. physo^ 

 Tcermina sp. n., occurs in Physokermes abietis. 



F. Vejdovsky* discusses the same forms and the interest of the dis- 

 covery that fungoid organisms of this sort seem to be constant symbions 

 of Coccids. This may lead to some new view of the economy of these 

 insects. 



Insect Bionomics.t — F. Merrifield pleads for a fuller study of 

 the life and habits of insects and their environmental relationships, as a 

 step towards the better understanding of the web of life. Among special 

 points discussed in his address the following may be mentioned. Failure 

 of food is not often the cause of the extinction of herbivorous insects, 

 but rather the numerous enemies they have to cope with. Many 

 characters seem to be biologically indifferent. Habits are often of 

 great biological importance, but many are not directly connected with 

 nutrition or reproduction, and seem to be merely expressions of the 

 joie cle vivre. 



Procession of Cnethocampa pinivora.f — H. H. Brindley records 

 some observations on a "wild" procession of Gnetliocampa pinivoi'a in 

 the Landes (Cap Ferret woods), confirming many of Fabre's results.. 

 The procession was attacked by Tachinid flies {Dexodes machairopsis). 

 The flies propped themselves up on their wings, pushed at the larvfe 

 with their feet, and attempted to inject their eggs on the bare ventral 

 surface. They avoided the hairs of the larvfe, which possess urticat- 

 ing properties. A useful summary of known facts concerning the pro- 

 cession is given, but it is pointed out that much still remains obscure. 



y. Myriopoda. 



Tracheae of Julus.§ — H. E. Ziegler communicates some observations 

 on the tracheal system of Julus. He calls attention, for instance, to 

 the multitude of fine trachege which pass from the 4th and 5th segments 

 towards the head. The stigmatic pouches are too thick-walled tO' 

 have any direct respiratory significance ; they give origin to the trachcEe, 

 but the two pairs of stigmatic pouches in each double segment do 

 not give rise to similar tracheae. From the anterior pair there arise 

 two bundles of very fine trachea3, which go to the musculature of the 

 limbs and to various organs, but do not branch. These are comparable 

 to the trachea of Peripatus. From the posterior pair of stigmatic 

 pouches there arise trachese with a wider lumen and a relatively thick 

 hypodermis. These resemble the tracheal of Insects. Many detailed 

 points of interest are noted, but a full account will be published by 

 H. Krug, one of Professor Ziegler's students. The following conclu- 

 sions are drawn : — 



1. The tracheal ponches of true Tracheata are segmental organs. In 

 Diplopoda they are in very close relation with the limbs, and serve for 



* SB. k. Bohm. Ges. Wiss., xix. (1906) p. 6-12 (1 fig.), 



t Pres. Address, Entomol. Soc, 1907. 



i Proc. Camb. Phil. Soc, xiv. (1907) pp. 98-104. 



§ Zool. Anzeig., xxxi. (1907) pp. 77G-82 (3 figs.). 



