ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
463 
demonstrable for Invertebrates, is likely to be to some extent demon- 
strable for Vertebrates as well, is one of the author’s contentions. 
y. General. 
Phosphorus in the Tissues.* — Drs. L. Lilienfeld and A. Monti have 
made a series of microchemical investigations bearing upon the localiza- 
tion of phosphorus in the tissues both of plants and of animals. Their 
general result is that young cells capable of reproduction are always 
rich in phosphorus, while much differentiated cells, in which the power 
of reproduction tends to be lost, have nuclei poor in phosphorus. 
B. INVERTEBRATA. 
Mollusca. 
y. Gastropoda. 
Olfactory Organs of Helix.f — Dr. A. B. Griffiths contends that 
Sochaczewer’s experiments, by which he showed that the tentacula of 
Helix poraatia are not olfactory organs, were untrustworthy from his 
use of turpentine, which gives off a vapour that is irritating to the 
sensitive tissues generally. If snails are placed on flat slabs, the edges 
of which are smeared with eau de Cologne, methyl, ether, or ethyl 
acetate, liquids the vapours of which are not irritants, such as have the 
tentacula removed gradually approach the edges of the slabs, while 
those whose tentacles are uninjured turn away from the edges. He 
concludes, therefore, that the tentacula are the seat of the olfactory 
organs in Helix. 
Opisthobranchs of the ‘ Hirondelle.’ t— Dr. R. Bergh describes the 
Opisthobranchs collected by the Prince of Monaco on the ‘ Hirondelle.’ 
The work is chiefly descriptive of the structure of a few species, some of 
which are new. Pleurobranchillus is a new genus, resembling Pleuro- 
brancJms in some points. 
Histology of Muscle in Heteropods and Pteropods.§ — Herr J. 
Wackwitz has investigated species of Carinaria, Pterotrachea, Atlanta , 
Hyalea, Cleodora, Creseis, &c., and has compared their muscle with 
that of other molluscs. Within the relatively narrow range of the 
two groups above mentioned, there is great histological diversity as 
regards muscle. There are smooth fibres and striped fibres and grada- 
tions between them ; and both kinds of fibres occur in two forms, either 
poor in contractile substance and rich in medullary substance, or the 
reverse. In those molluscs which creep — a mode of locomotion more 
laborious than swimming — the contractile substance predominates. 
And since the medullary substance, through which compensation for 
waste is obtained, is relatively less, the muscle is adapted for powerful 
but slow activity. In Heteropods and Pteropods the reverse holds good. 
In regard to the occurrence of smooth and striped muscle, the author 
corroborates the conclusion that striped muscle is adapted for more 
energetic and rapid activity than smooth muscle. 
* Atti R. Accad. Lincei — Rend., cclxxxix. (1892) pp. 354-8. 
f Proc. Roy. Soc. Edin., xix. (1892) pp. 198 and 9. 
X ‘ Resultats Scientifiques,’ &c., iv. (1893) 35 pp., 4 pis. 
§ Zool. Beitr., iii. (1892) pp. 129-60 (3 pis.). 
