304 SUMMARY OF CURRENT RESEARCHES RELATING TO 



a frog from Kamerun. They have been previously noted by Gadow and 

 Boulenger. There are corresponding small tubercles on the female, and 

 there is no doubt that the filaments are highly developed tubercles. 

 Microscopic examination showed an inner cutis papilla and an epidermal 

 outer layer with numerous longitudinal ridges. There are nerve-endings 

 in the filaments, which are probably sensory. There may be other 

 functions, as is suggested by the presence of glands. 



Poison-glands of Scorpaenid Fishes.* — E. Pawlowsky has made a 

 histological study of the poison-glands of Scorpsena, Sebastes, and related 

 fishes. They are direct derivatives of the epidermis, the supporting 

 cells being compressed epidermic cells, and the glandular cells corre- 

 sponding to the unicellular albumen-glands in the skin. The new 

 formation of cells in the skin and in the glands is the same. Pawlowsky 

 emphasizes the close resemblance between the poison-glands and the 

 mucous-glands of Myxine. The only difference is that in the latter 

 there are mucous-cells as well as albumen-cells. The resemblance 

 between Scorpgenid poison-glands and those of the salamander is also 

 indicated. 



Tunicata. 



Influence of Spermatozoa of Tunicate on Ova of Sea-urchin.f — 

 M. A. van Herwerden observed the spermatozoa of Ciona intestinalis 

 swarming round the unfertilized ova of Strong ylocentrotus lividus. 

 Experiments led to the conclusion that they stimulated the ova to 

 parthenogenesis, but it could not be proved that spermatozoa actually 

 entered the ova. 



INVEBTEBRATA. 



Mollusca. 

 5. Lamellibranchiata. 



Minute Structure of Pallial Tentacles of Lima.J — L. E. GriflBn 

 describes the annulated adhesive tentacles of a species of Lima from the 

 Philippines. They show a remarkable resemblance to a tentacle of 

 Nautilus — a case of parallelism of development. A large nerve runs up 

 the centre ; radial muscles pass from the central region to all parts of 

 the periphery ; and strong longitudinal muscles lie in the spaces between 

 the radial fasciculi. The central portion of the nerve is composed ex- 

 clusively of fibres. Upon its surface is an almost continuous layer of 

 nerve cells, but more or less distinct aggregations of nerve-cells are found 

 at points corresponding to the annular ridges of the surface of the 

 tentacle. As in the Nautilis cirri the epidermal cells are high upon the 

 ridges, but very low in the grooves of the tentacles. On the outer sur- 

 face of the tentacle is a narrow longitudinal groove at the base of which 

 also the epidermal cells are very low. In some cases the epidermal 

 cells are crowded with mucous secretion. 



* Zool. Jahrb., xxxi. (1911) pp. 528-42 (2 pis.). 

 t Anat. Anzeig., xl. (1912) pp. 569-79 (3 figs.). 

 t Philippine Journ. Sci., vi. (1911) pp. 327-9 (4 figs.). 



