ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 305 



ova are frequently used up as nutritive material by their neighbours, 

 so that the nutritive cells of the Lithobius-ovary must bs regarded as 

 abortive or unsuccessful ova. 



The cell-lineage is as follows : — 



Indifferent cells of the germinal epithelium 



Germ-cells Follicle-cells 



Ova Nutritive cells 



Successful ova Nutritive (abortive) ova 



The general result, it will be observed, is to corroborate completely 

 in reference to Lithobius, the conclusions which were established by 

 Heymons from his study of Scolopendra. 



Comparative Morphology of Chilopoda.* — Dr. Karl W. Verhoeff 

 discusises some of the results obtained by Heymons in his recent study 

 of the embryology of Scolopendra.^ First, in regard to the appendages 

 of the head, he points out the differences between Heymons' nomenclature 

 and his own, and adduces reasons for believing that Heymons' conclu- 

 sions suffer from the fact that he has confined his observations too ex- 

 clusively to the early stages of development. Again, in regard to the 

 number of segments in the legs, whilst most authors give seven as the 

 typical number, VerhoetF finds six only, and Heymons eight. But 

 Heymons includes the claw as a distinct segment, although in post- 

 embryonic life it does not contain a cavity, and the other segment is the 

 trochanter which is only present in rudiment in the posterior legs of 

 Scolopendra, but is distinct in the anterior. Heymons' results convince 

 Verhoeff that while in Lithobius the six-jointed condition is the primary 

 one, in Scolopendra it is secondary. Further, he does not agree with 

 Heymons' nomenclature for the newly discovered small segment behind 

 the genital segment. He considers that the name genital segment must 

 be retained for the segment to which it has hitherto been applied, and 

 the name post-genital segment be given to Heymons' newly discovered 

 segment. 



Resistance of Myriopods to Asphyxiation.^ — Dr. G. Eossi has 

 made a number of experiments. It seems that millipedes (lulus) sur- 

 vive prolonged immersion, exhibit no sign of discomfort, and retain for 

 a long time their wonted vigour. Centipedes (Scolopendra, Lithobius, 

 Scutigera, &c.), on the other hand, show plain signs of discomfort when 

 thrown into water, they soon become rigid, and never survive more than 



* Zool. Anzeig., xxv. (1902) pp. 118-20. t Cf. this Journal, ante, p. 41. 



' X Ex Bull. Soc. Entomol. Ital., xxxiii. (1901) 31 pp. 



