ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 187 



of between 0" aud 2° C, abnormal embryos can be produced, a certain 

 percentage of which may show degenerate eyes. 



Lack of light does not influence the development of the eyes of 

 Fmidiilus, and Loeb inclines to the view that some internal mutational 

 change in the germ, and not the lack of hght, may account for the 

 blindness of certain cave fishes and salamanders. 



Tentacles of Blenny.* — H. A. Baylis has studied the two pairs of 

 branched tentacles (supra-orbital and nasal) on the head of Blenniits 

 gattoriKjim, and describes their minute structure — e.g. two forms of 

 mucous cells, fusiform cells apparently connected with nerve-fibres, 

 very large elongated cells which usually extend through the whole 

 thickness of the epidermis. It appears that the tentacles are very 

 sensitive to touch, whether the stimulus comes from an article of food 

 or an inanimate object. It is possible tha.t the tentacles are sensitive 

 to disturbances in the water, but no evidence was forthcoming. C. Tate 

 Regan suggests that they may serve to gauge the amount of space in the 

 crannies. 



Habits of Cottus bubalis.t— R. Elmhirst writes an interesting 

 note on the habits, especially in relation to breeding, of Cottus hubalis, 

 which he has had opportunities of observing in the tanks at the 

 Millport Marine Biological Station. A female deposited eggs on a 

 stone about the end of February, and the male after fertilizing them 

 mounted guard over them and never went more than a few inches away 

 from them for five or six weeks. No other male was allowed to 

 approach the stone. No trace of nest-l:)uilding by the male was 

 observed. Later, a second female spawned on the same stone, and the 

 male was observed in the act of fertilizing them. He was brilliantly 

 coloured ; pale orange ventrally, pectoral fins white, spotted and 

 blotched with colour. The fins twitched constantly as the male jumped 

 and turned excitedly, and sometimes dashed under the stone below the 

 female. In this position semen was ejaculated from the penis, which 

 was protruded 1 1 mm. on to the egg-mass. The tentacles over the eye 

 were very distinct and quivering, and the maxillary tentacle was very 

 erect. Several times the male darted open-mouthed at the female and 

 engulfed half her head in his mouth. The rate of the respiratory act 

 was 36 per minute, and very full ; that of the female not so full. The 

 normal rate varies between 28 and 32. A third female spawned on the 

 same stone, and all three died within a few days of spawning. 



Lapillus of Fishes.J — ^- E- Shepherd gives an account of the 



\-aried shapes of the lapillus or otolith found in the recessus atrkuli 



portion of the ear-labyrinth of Teleostean fishes. He has previously 



- dealt with the "asteriscus" and many "sagittt^." Twenty-four types 



are figured. In sturgeon the place of the lapillus is taken l)y otoconia 



* Journ. Linn. Soc. (Zool.) xxxii. (1915) pp. 295-306 (2 pis. aud 1 fig.), 

 t (rlasgow Naturalist, vii. (1915) pp. 13-6 (3 figs.). 

 X Zoologist, xix. (1915) pp. 257-62 (1 pi.). 



