ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 39 



on one side at about the middle of its length and the genital opening 

 at its posterior end, just behind the articulation of an external movable 

 t'orwardly directed serrated bone (the " ctenactinium "). Anteriorly the 

 appendage ends in a long slender bone extending forwards to beneath 

 the chin, curved towards the side on which the serrated bone lies and 

 away from that on which the anus opens. For this bone the name 

 '' toxactinium " is proposed. The priapium is an intromittent organ : it is 

 unlike any other copulatory organ among Fishes. The vas deferens is 

 coiled in a remarkable way to form a sort of epididymis. Another 

 remarkable feature is the wide separation of the openings of the urinary 

 and genital ducts. 



Statocysts of Marine Invertebrates.* — W. v. Buddenbrock has 

 continued his study of these structures, with especial reference to 

 Arenicola, Myxkola infundibulum, Branchiomma vesiculosum, and Solen 

 vagina. He finds that Branchiomma can bore tail foremost vertically 

 into the mud, and the same is probably true of Myxkola. The statocysts 

 effect an increase of the tonus of the longitudinal muscles on the side 

 that is undermost, and cause their contraction. There is also a musculo- 

 sensory regulation which always tends to bring the tail parallel to the 

 head. The two factors co-operate to bring about the vertical positively 

 geotropic boring. If both statocysts are removed from Branchiomma, 

 it loses the power of boring vertically from any initial position. The 

 removal of one statocyst has no effect. The statocysts have nothing to 

 do with the perception of oscillations in the water. 



INVERTEBRATA. 



Moilusca. 

 a. Cephalopoda. 



Minute Structure of Argonaut's Food-canal. f — W. Gariaeff has 

 studied the gullet and the csecurn of the female Argonaut. The former 

 shows a thick-layered cuticula perforated by fine canals, then the 

 epithelium with distal basal corpuscles, and then a fibrillar basal 

 membrane in continuity with the connective-tissue, in which there are 

 obliquely striped muscle-fibres. The lumen of the caecum is divided 

 by a large number of septa covered with high cylindrical ciliated 

 epithelium. There are also mucin cells and strongly developed glan- 

 dular cells. 



Minute Structure of Cuttlefishes.! — F. R. Tippmar has made a 

 study of various parts of numerous Cephalopods. He deals with the 

 disposition of the muscle-fibres in the mantle, the structure of the skin 

 and subcutaneous connective-tissue, the integumentary structures (in- 

 cluding the luminous organs of Mastiyoteuthis), the innervation of the 

 mantle, and the body musculature in general. He has also notes on 

 the post-embryonic development of Calliteuthis reversa. 



* Zool. Jahrb., xxxiii. (1913) pp. 441-82 (13 figs.). 



t Anat. Anzeig., xiv. (1913) pp. 38-45 (2 pis.). 



t Zeitschr. wiss. Zool., cvii. (1913) pp. 509-73 (2 pis. and 39 figs.). 



