( 421 ) 

 SUMMARY 



OF OURHENT RESEARCHES RELATING TO 



ZOOLOaY AND BOTANY 



(principally Invertthrata and Cryptogamia'), 



MICROSCOPY, &c., 



INCLUDING ORIGINAL COJDIUNICATIONS FROM FELLOWS AND OTHERS.' 



ZOOLOGY. 



A. GENERAL, including Embryology and Histology 

 of the Vertebrata. 



Protoplacm and its Powers of Resistance.f — Dr. 0. Loew classes 

 protoplasm i;s sensitive and resistant, the former readily allowing a 

 breaking-up of the cell-organization and a consequent chemical 

 rearrangement of the molecular albumen, whilst the latter does not 

 immediately show disintegration of layers adjoining that affected by a 

 chemical or other stimulus, and is, in short, harder to kill. Sphcero- 

 plea and Vaucheria are extreme examples, but all intermediate stages 

 occur. 



The chemical characteristics of a cell are closely bound up with 

 the cellular organization. A chemical reaction on living protoplasm 

 can only take place in more or less resistant protoplasm. In sensitive 

 cells the cell is killed before the reaction can take place, e. g. alkaline 

 silver solution kills infusoria at once, but is to some measure reduced 

 by the cells of the frog's kidney, whilst it is energetically reduced by 

 Spirogyra. Loew goes on to consider the action of strychnine, ammonia, 

 and other poisons, and is disposed to believe that their action is pro- 

 portional to the weakness of the solution, the unaffected portions in 

 resistant cells repairing slight damage. A comparative toxicology 

 is thus suggested. 



Power of resistance to chemical stimuli is not necessarily equivalent 

 to power of resistance to other stimuli (e. g. heat, drought, &c.), and 

 variations of temperature alter the resistance in like cells, heat making 

 the organism more labile and easy to destroy. 



Problem of Fertilization and of the Isotropy of the Ovum.l — 

 Dr. 0. Hertwig discusses the phenomena .of heredity. In his first 



* The Society are not intended to be denoted by the editorial " we," and they 

 do not hold themselves responsible for the views of the authors of the papers 

 noted, or for any claim to novelty or otherwise made by them. The object of 

 this part of the Journal is to present a summary of the papers as actiudlij published, 

 and to describe and illustrate Instruments, Apparatus, &c., which are either new 

 or iiave not been previously described in this country. 



+ Arch. f. d. Gesammt. Physiol. (Pfliiger), xxxv. (1885) pp. 506-16. 



J Jenaisch. Zeitschr. f. Naturwi^s., xviii. (1885) pp. 276-318. 



