RECENT ADVANCES IN SCIENCE 401 



Nelson has carried out investigations " On the Origin, 

 Nature, and Function of the Crystalline Style of Lamelli- 

 branchs " (Jour. Morph. vol. xxxi. June 191 8) on material 

 from six marine and fresh-water species. The style develops 

 from the posterior region of the stomach. By its rapid rotation 

 it aids the digestive processes in the stomach very materially, 

 and in it is stored a mass of amylolytic ferment for utilisation 

 at the feeding periods. Undigested food-remains that escape 

 from the stomach are returned by ciliary currents in the in- 

 testine through the core of the style. 



Other papers include : Packard, " A Quantitative Analysis 

 of the Molluscan Fauna of San Francisco Bay " (Univ. Cal. 

 Pub. Zool. April 191 8) ; Whittaker, " The Relationship of the 

 Marl Fauna of Mackay Lake, Ottawa, to the Present Molluscan 

 Fauna of the Lake " (Ott. Nat. April 191 8). 



It has always been tacitly assumed that the larval insect 

 possessed olfactory organs, but until the publication of the 

 paper by Mclndoo on " The Olfactory Organs of a Coleopterous 

 Larva " (Jour. Morph. vol. xxxi. June 191 8) they had never 

 been described. The author describes them as being similar 

 to those in the adult, and distributed to the number of about 

 1,359 on the antennae, mouth-parts, thorax, and legs. 



Other papers include : Lim, '' Period of Survival of the 

 Shore-Crab (Carcinas mcenas) in Distilled Water " (Pro. Roy. 

 Soc. Edin. 191 8) ; Hay and Shore, " The Decapod Crustaceans 

 of Beaufort, N.C., and the Surrounding District " (Bull. Bureau 

 Fish. Washington, April 191 8) ; McLean, " Revision of Some 

 Phacopid Genera " (Ott. Nat. April 191 8) ; Sanford, " Ex- 

 periments on the Physiology of Digestion in the Blattidae " 

 (Jour. Exp. Zool. vol. xxv. April 191 8). 



Vertebrata. — The " Differentials in Behaviour of the Two 

 Generations of Salpa democratica, Relative to the Temperature 

 of the Sea " (Univ. Cal. Press, March 191 8), by Michael, throws 

 light on the relation of this species to its environment. The 

 main conclusions arrived at are that the differences in dis- 

 tribution between solitary and aggregate forms are as definite 

 as the differences of structure, and the former differences cannot 

 be explained by the seasonal succession of the two generations. 

 Hydrographic changes or variations in viscosity also cannot 

 account for the differences. Finally the author concludes 

 that " Contrary to the prevailing plankton concept, Salpa 



