ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 181 



fi, Onychophora. 



West Australian Onychophora. — W. J. Dakin {Froc. Zool. Sor. 

 London, 1920, ;-567-89, 5 pis.).' There are two West Australian varieties 

 of Peripatus, sub-genus Peripatoides. The northern form, Peripatoides 

 occldentalis, has always sixteen pairs of legs : the southern form, P. occi- 

 dentalis var. (jUp.sH, has only fifteen pairs. It appears that P. occidentalis 

 approaches most closely to P. leiickartii, but it stands apart from other 

 species, e.g. in the presence of extraordinarily long crural glands opening 

 on the first pair of legs. Among the most important general results of 

 the paper are the following, probably applicable to most Onychophora. 

 The cells of a certain part of the so-called nephridium, that which opens 

 into the coelomic vesicle, bear long and well-developed cilia. So these 

 are not confined to the reproductive organs. Crural glands sometimes 

 occur in the female, but do not seem to have any ducts. The tracheae 

 of Peripatus possess a characteristic spiral supporting fibre (disputed for 

 many years). The trachea, although running a separate course for 

 some distance from the tracheal pit, eventually branch. As GafFron 

 discovered, the spermatogenesis does not occur in the testis but in the 

 seminal vesicles. J- A. T. 



y, Araclinida. 



Malformations in Ticks. — L. E. PiObinson {Parasitology, 1920, 

 12, 175-9, 5 figs.). Description of a number of malformations in 

 Dermacentor atrosignatus (deformity of hypostome), AmUgomtna hebrseum 

 (absence of left eye and deformity of scutum and spiracle), A. cajennense 

 (fusion of coxffi (I. and II.) and suppression of normal coxal armature);^ 

 Hgadomma segyjjtium (oblique curvature of body axis, and in another 

 case suppression of spiracle and adanal shields on the right side of the 

 body). Snch malformations are probably the result of some mutilation 

 of the tii^k during the course of the preceding nymphal phase. In the 

 course of engorgement, particularly as the state of repletion is approached, 

 the chances of injury to which a tick is exposed are numerous, owing 

 to the intentional or accidental scratching and rubbing of the infested 

 parts of its body by the host, and the remarkaljle power of regeneration 

 of damaged or lost appendages, which the ticks, in common with other 

 Arthropods, have developed, must ensure the survival of many individuals 

 which otherwise would perish. J. A. T. 



Regeneration of Mouth Parts and Legs in Ticks, — Geoege H. F. 

 NriTALL {Parasitology, 192o, 12, 7-2G, G figs.)- The mouth parts of 

 larvae of Argas persicus were mutilated shortly after the larva abandoned 

 the host fully gorged. The various structures were differently affected 

 in the first-stage nymph. The palps are not regenerated, but appear as 

 stumps, occasionally with an article or two regenerated. The hypostome 

 is perfectly regenerated when amputated at any point short of its base. 

 If cut at its base the regenerated hypostome may be slightly deformed. 

 The digits of the cheliceras are usually deformed to a varying degree, 

 but considerable regeneration occurs. As the tick develops towards 

 maturity the power to regenerate palps and digits increases. In 



