ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 647 



and Neoniphargus fultoni. The third of these is of especial interest, 

 inasmuch as, although an inhabitant of surface-waters, it is totally with- 

 out eyes, and is comparable in this respect to Niphargus pulchellus. 



Annulata. 



Respiration in Polychseta.* — J. Bounhiol has made a detailed study 

 of the respiratory system and functions in Polycbaata. We can only give 

 some of his general results. 



The branchiae of annelids are pectinate or branched organs, some- 

 times situated on the various segments of the body (Euuicidaa, Areni- 

 colidae), sometimes exclusively cephalic (Terebellidae), always very 

 vascular, and of considerable respiratory activity, discharging three- 

 quarters or more of the total respiration, while the skin is responsible 

 for about a quarter. There is always cutaneous respiration, undoubtedly 

 the primitive mode. The organs called branchiae in Cirratulidae and 

 Serpulidae are not gills, but prehensile organs. The organs called lym- 

 phatic or cceliac branchiae in forms with colourless blood have no particular 

 respiratory role. 



The fluid of the body-cavity has a respiratory significance far inferior 

 to that of coloured blood, and it has none unless it contain some coloured 

 corpuscles. The species with colourless blood are physiologically in the 

 same position as those with only a ccelomic fluid. 



Regeneration of Alimentary Canal in Rhynchelmis limosella.j — 

 O. Winkler removed 5-10 segments from the anterior end and observed 

 the formation of a new mouth (from ectodermic invagination) and of a 

 new pharynx (from the old gut). He gives a detailed account of the 

 regeneration process, and describes a number of experiments. It is 

 interesting to notice the close correspondence in this case between the 

 regenerative and the embryonic development. 



Sense-Organs of the Polychset Proboscis. J — A dele Oppeuheimer 

 gives an account of certain sense-organs of the proboscis of Itliynchobolus 

 clibranchiatus, which take the form of well-differentiated papillae, occur- 

 ring over almost the entire surface of the everted proboscis, elevated 

 above the surrounding surface, and covered by a cuticle which is reduced 

 to about two-thirds of the thickness it bus elsewhere. 



There are two or three spindle-shaped cells in a papilla, each termi- 

 nating — either below the cuticle or more probably at the very apex of 

 the papilla — in what is clearly a sensory structure. Moreover, each of 

 these cells tapers gradually at its base into a nerve-fibre. These nerve- 

 fibres are connected either directly or indirectly — through the inter- 

 vention of a peripheral nerve-plexus— with the eighteen longitudinal 

 nerves of the proboscis. There are two basal nuclei belonging to cells 

 which probably have the function of cover-cells. Into each papilla there 

 enter, besides nerve-fibres, connective-tissue fibres in close connection 

 with a finely granular substance, of which there is a particularly dense 

 and deeply staining layer immediately under the cuticle. 



* 



Ann. Sci. Nat. (Zool.), xvi. (1902) pp. 1-80. 

 t SB. Bohm. Ges. Wiss., 1902, No. 12, 34 pp. (2 pis.). 

 X Proc. Amer. Acad., xxxvii. (1902) pp. 553-62 (6 pis.). 



