246 SUMMARY OF CURRENT RESEARCHES RELATING TO 



other plants, rather than an impediment to the development of tabes 

 from tne same plant. Specific stimulants arc supposed to reside in the 

 pollen-grains which can call forth the sugar secretion unless the pollen 

 be that of the plant itself. Different hereditary complexes stimulate 

 pollen-tube growth and in all likelihood promote fertilization ; like 

 hereditary complexes are without such effect. It may be that in 

 animals the external portions of the membranes of the ovum are 

 functionally zygotic in character. 



INVERTEBRATA. 



Mollusca. 

 a - Cephalopoda. 



Japanese Cuttlefish.* — C. Ishikawa describes Enoploteuthis chunii 

 sp. n., and compares it in detail with the other known species, E. leptura, 

 from the coast of West Africa. The differences refer very largely to 

 the proportions of parts. There are six rows of luminous organs on the 

 ventral surface of the head in E. leptura, and five in the new species. 

 The radula is very simple, and very like that of Thaumatolampus. 

 Each row has seven denticles, with the formula 3221223. Five females 

 were found, all with spermatophores attached dorsally under the mantle. 

 The male is unknown. 



C. Ishikawa and Y. Wakiyat describe Mo rote ut his lonnbergi sp. n., 

 which has thirteen pairs of hooks' on the prehensile part of the tentacle 

 and seven or eight suckers on the fixing apparatus. Very remarkable 

 is the warty or plaster-like appearance of the mantle previously noticed 

 by Lonnberg in another species. It is due to interesting lines of eleva- 

 tions and depressions of the dermis. The same authors also describe J 

 parts of a gigantic squid, probably Moroteuthk robusta, from the stomach 

 of a sperm whale. The mantle was probably about four feet long. 

 The dermis of the mantle shows the " plastered structure." 



y. Gastropoda. 



Cells with Double Nuclei in Spermatogenesis of Paludina 

 vivipara.§ — Cesare Artom finds that some of the growing spermatocytes 

 show two nuclei. Each of these is perfectly normal, and the two 

 remain independent during the growth of the spermatocytes, and during 

 the maturation and reduction processes. Artom supposes that the 

 presence of two nuclei implies that the division of the cytoplasm of a 

 spermatogonium has been suppressed. It may be that these binucleate 

 elements give rise to the giant spermatozoa which occasionally occur. 



* Journ. Coll. Agric. Univ. Tokyo, iv. (1914) pp. 401-13 (2 pis.). 

 t Journ. Coll. Agric. Univ. Tokyo, iv. (1914) pp. 445-60 (2 pis.). 

 t Journ. Coll. Agric. Univ. Tokyo, iv. (1914) pp. 435-43 (2 pis.). 

 § Atti (Rend.) R. Accad. Lincei Roma, xxiii. (1914) pp. 45-7. 



