636 SUMMARY OF CURRENT RESEARCHES RELATING TO 



possessed by these animals may most properly be called a sense of 

 smell, and they are the lowest animals in which any such sense has 

 hitherto been noticed. It was not found practicable to determine by 

 experiments whether the sense is restricted to any special part of the 

 organism or is diffused over the whole. 



Protozoa. 



Ciliation of the Hypotrichous Infusoria.* — J. van Kees, in a 

 preliminary paper to a larger work on the marine Infusoria, describes 

 in considerable detail the ciliation (more especially) of Styloplotes 

 grandis n. sp. A new diagnosis is given of Euplotes longipes, whose 

 ciliation is compared with that of the former. 



Species of Vorticellse.— Mr. W. Saville Kent in the third 

 vol. of his ' Manual of Infusoria ' gives a plate constituting a very 

 useful key to the numerous species of the genus Vorticella, each of 

 the forty-two species being represented in diagrammatic outline at its 

 most typical condition of extension. 



Acinetidse.t — E. Maupas has studied the forms obtained by him 

 in Algiers and at Eoscoff in Brittany, and describes at length 

 Svhcerophrya magna, Podophrya limbata, Acineta pusilla, A. Jolyi, 

 A. emaciata, A. fcetida, HemopJirya thouleti, and H. microsomia. An im- 

 portant observation is recorded as to the ingestion of food by S. magna. 

 When an Infusorian is caught a rupture in its cuticle is produced at 

 the point of contact with the tentacle. According to the author the 

 axillary substance of the latter consists of clear homogeneous sarcode 

 continuous with that of the body of the Acinetan, and this passes into 

 the Infusorian, and probably accelerates its death. The tentacle now 

 increases greatly in thickness, due without doubt to the afflux of 

 sarcode from the Acinetan, from which a current is thus established 

 in the direction of its prey, not, however, visible in consequence of 

 the transparency of the sarcode stream. The latter mixes freely with 

 the contents of the victim's body, and loading itself with assimilable 

 substances returns in the inflowing stream, which is so plainly visible 

 by reason of the opaque granular particles held in suspension. This 

 phenomenon is directly comparable with the sarcode circulation in the 

 extended pseudopodia of Foraminifera or cyclosis in plant-cells, 

 though in the former both streams are visible.! 



The author adds a full summary of the general facts which the 

 special studies of the species have, in his opinion, established in 

 regard to the structure and histological constitution of the Acinetan, 

 and some of the controversies which have existed on the subject. 



The first question considered is whether any naked Acinetidae 

 exist, destitute of all external covering, with bodies simply composed 



* Kees, J. van, ' Zur Kenntniss der Bewirnperung der Hypotrichen Infusorien 

 nach Beobachtungen an Styloplotes grandis n. sp. trad Euplotes longipes? Amster- 

 dam, 1881, 44 pp. and 1 pi. 



t Arch, de Zool. Exper. et Gen., ix. (1881) pp. 299-3G8 (2 pis.). 



% Cf. for a discussion on the importance of this j>henomenon Kent's ' Manual 

 of the Infusoria,' iii. (1882) pp. 803-5. 



