XXU PBOCEEDINGS OF THE 



although disfigured by some faults both of omission and com- 

 mission, will be found exceedingly useful to the student. The 

 -anatomy of the circulatory system of the Spiders has been eluci- 

 dated by M. Claparede, by an investigation of this apparatus 

 in the genus Lycosa, originally printed in the Memoires de la 

 Societe de Physique et d'Histoire Naturelle de Greneve, but re- 

 printed in the Annales des Sciences JSTaturelles, and translated 

 in the Annals and Magazine of Natural History. 



On the Myriopoda we have to record the production of no such 

 works as those just alluded to ; but two important geographical 

 memoirs have lately appeared, — one by M. Humbert, " On the 

 Myriopoda of Ceylon," in the Memoires de la Societe de Physique 

 et d'Histoire Naturelle de Greneve ; the other, " On the Myriopoda 

 of North America," by Dr. H. C. "Wood, in the Transactions of 

 the American Philosophical Society. Both these works contain 

 carefully elaborated descriptions of the genera and species ; and 

 the latter enters in some detail into the discussion of the mode of 

 classification : both are illustrated with good figures. We may 

 also indicate a paper by Professor Peters, entitled " A Revision of 

 the Myriopoda of the family Polydesmi contained in the Hoyal 

 Museum of Berlin," published in the Monatsbericht of the Berlin 

 Academy of Sciences for 1864. 



In treating of the entomological literature strictly so called 

 of the past two years, we may commence by the consideration of 

 one or two papers which have a general bearing independently 

 of their mere entomological interest. One of these is the production 

 of an American entomologist, Mr. B. J. Walsh, who calls attention 

 to certain difierences occurring in insects admitted to belong to 

 the same species, in accordance with the nature of the food-plant, 

 and endeavours to apply the results thus obtained in support of 

 the theory of the origin of species by evolution from preexisting 

 forms. To such difi^erent forms of the same species Mr. Walsh 

 gives the name oi phytopJiagic varieties ; and he assumes that by 

 their being excluded from intercourse with the forms feeding on 

 other food-plants they may, in course of generations, give rise to 

 fliytofTiayic races, or even to what he calls phytophagic species, 

 which would be either averse to, or quite incapable of, interbreed- 

 ing. If this view can be maintained, it is evident that the hypo- 

 thesis above alluded to will derive most important support from 

 it. A memoir vs^hich will render great assistance to any European 

 entomologist who will attempt to work out the problem enunciated 

 by Mr. Walsh is Dr. Kaltenbach's " Deutschen Phytophagen," 



