ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 599" 



secretions, such as mucin, silk, wax, &c. ; the pigments ; the skeletal 

 tissues ; the genital secretions, and so on. The author, who has himself 

 made important contributions to comparative physiology, is to be con- 

 gratulated on having done with scholarliness and judgment a piece of 

 work which will be of great utility to students and investigators. 



Electrical Criterion of Vitality.* — Augustus D. Waller reports- 

 the results of experiments conducted by aid of an electrical criterion — 

 " blaze-reaction " — distinguishing between the living and not-living state. 

 He refers first to the case of the hen's egg, which is particularly interest- 

 ing, " for while we cannot tell a priori with any assurance whether or 

 no a dormant egg will give the reaction characteristic of living matter, 

 we may — after having learned by experience that it does not do so — 

 expect to find the reaction make its appearance with the progress of 

 development by incubation. And as a matter of fact, we find that this 

 is what happens." The presence of a blaze-current is a certain sign 

 that development has progressed within the egg. 



Waller also finds that a crystalline lens is a good object upon which 

 to study the nature of blaze-currents, Here again a blaze-current is a 

 physical sign of the " living " state. 



' In another paper, A. Durig f describes observations which make it 

 impossible, he says, to regard the appearance of blaze-currents as a 

 specific property of living tissue. It is much more probable that they 

 are to be considered as special manifestations of certain epithelial tissues. 

 Nor can the presence of exclusively polarisation effects be taken as the 

 sign of death in a tissue, since these may occur alone and typically in 

 living organs. 



Relation between Weight of Liver and Total Surface.} — E. Maurel 

 finds that in guinea-pig, rabbit, clog, fowl, &c, the weight of the 

 liver bears (except in early stages) a constant ratio to the total surface 

 of the body. The ratio is constant for the species, or for the variety of 

 a heterogeneous species like the dog. The volume of the liver is affected 

 by various factors, e.g. its antiseptic role, but especially by the nature of 

 the food. 



Coloration of Myxinoids.§ — Bashford Bean notes that Myxinoids 

 run the gamut of coloration common to deep-sea forms. Thus in a 

 range of species they pass from black (Myxine circifrons) into dark 

 purples, thence to violets and lavenders, then into " meaningless " greys, 

 sometimes uniformly coloured, sometimes shaded (lighter ventrally, 

 darker dorsally). In some cases lack of pigmentation in definite regions 

 becomes a lather conspicuous feature, thus the tips of the barbels are 

 generally white and the median lines may be unpigmenbed. 



The author reports the occurrence of complete albinism (I in 800) in 

 Homea burgeri, of partial albinism in H. stonti, and of brilliant motley 

 colouring in H. polytrema. 



Studies on Cyclostomes.|j — L. Plate contributes a first part of a 

 series of studies of Cyclostomes, in which he describes twenty species of 



* Proc. Roy. Soc. London, lxxi. (1903) pp. 184-93, 194-211. 



+ Tom. rit , pp. 212-9. t Comptes Rendus, cxxxvi. (1903) pp. 316-9. 



§ Amer. Naturalist, xxxvii. (1903) pp. 295-8 (3 flsrs.). 



II Zonl. Jahrb., ii. (1902) suppl. vol. v. pp. 651-74(1 pi.). 



