ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 49 



accompanied by circulatory and respiratory troubles of toxic origin, may 

 have as their consequence, eitber tbe dissemination of the eggs by a 

 pelagic form (epitoky), or simply the expulsion of the eggs by a rupture 

 in the integument of a sedentary form (matricidal epitoky.) These facts 

 show once more the great importance of external and internal intoxi- 

 cation in the life-history of organism?, and in particular the importance 

 of the role of marine Algae." 



Sensory Cells in. Proboscis of Polychaets. * — Hans AVallengren has 

 studied the proboscis in a number of genera, and finds that sensory cells 

 are restricted to the papillas. In Nephthys and Phyllodoce they are 

 radially arranged, but not integrated into multicellular organs as in 

 Glycera and Goniada. The sensory cells penetrate the cuticula peripher- 

 ally, and in Glycera, if not also in others, they terminate in a kind of 

 brush. It seems likely that these free ends are retractile. Proximally 

 the cells may extend unbranched towards the central organ (as in 

 Nephthys), or they may divide like the letter T below the base of the 

 papilla?. The subcutaneous nerve-plexus is very richly developed in the 

 wall of the proboscis. It seems likely that the function is tactile, or both 

 tactile and gustatory. 



Commensal Oligochaete in New England, f — Prof. M. A. Willcox 

 describes a small Oligochaete, probably identical with Chsetogaster Hmnsei 

 von Baer, which occurs on snails belonging to the genera Physa and Plan- 

 orbis, in a small stream at Willesley. The worms occur apparently free on 

 the head and within the respiratory cavity of the snail, and are probably 

 not parasitic. They reproduce by fission, and chains consisting of three 

 persons are frequent, but it is rare to find colonies with more persons 

 than this. The worms differ from the European forms chiefly as regards 

 the number and arrangement of their setae, but it is uncertain whether 

 this does or does not constitute specific difference. 



Nematohelminthes. 



Phagocytic Organs in Nematodes. J — E. P. Golowin has made a 

 detailed study of the tuft-like bodies or phagocytic organs in many 

 different nematodes, both parasitic (Ascaris lumbricoides, A. spiculigera, 

 A. ostroumovi sp. n. from the sturgeon (Acipenser ruthenus), Filaria 

 papillosa) and free-living forms, — Oncholaimus vulgaris, Symplocostoma 

 longicolle, Aniicoma pellucida, Anguillula oxopltila, &c. In the large 

 parasitic forms the tuft is known to consist of a large central nucleus 

 and small roundish " terminal organs," sometimes with chromophilous 

 central corpuscles. In the small free-living forms there are ovoid organs 

 with a large reticular nucleus and numerous rod-like or roundish 

 chromophilous granular bodies, sometimes with small end-organs on the 

 external surface. They lie on the inner side of the musculature, some- 

 times in groups, sometimes distributed over the whole body, and in 

 Cyatholaimus ocellatus in longitudinal rows. In the small forms intra 

 vitam coloration of the phagocytic organs alone — apart from the rest of 

 the body — was successfully effected. 



* Jenaische Zeitschr. Naturwiss., xxxvi. (1901) pp. 165-80 (1 p].). 

 t Amer. Nat., xxxv. (1901) pp. 905-9. 



X Beobachtungen von Nematoden, Kasan. 1901, 149 pp. and 3 pis. (in Russian). 

 See Zool. Ccntralbl., viii. (1901) pp. 751-2. 



Feb. 10th, 1902 E 



