2018 Journal of Applied Microscopy 



The author returns to a memoir pub- 

 Gautler, Armand. Chemical Basis of Varia- j-gj^g^j -^^ ^ggg ^^^t variations which 

 tion. Comptes Rendus, 133 : 570-572, , , , . . r 



igoi. mark .the begmnmg of a new variety are 



detectable in the chemical composition 

 of the cells, and this makes a sudden appearance of a variation possible without 

 intermediate steps. A plant or animal organism may exhibit important varia- 

 tions with some abruptness ; these variations have their basis in plasmatic mole- 

 cular changes of particular organs. These plasmatic changes are referable to 

 reciprocal influences of other plasmas and to a less extent to changes in envi- 

 ronment and nutrition. a. m. c. 



The interesting fact is noted that in the 



Dean, Bashford. Reminiscence of Holo- ^f Heterodontus (Cestracion) iap- 



blastic Cleavage in Ovum of Cestracion. °° . 



Annot. Japon. 4: 35-41, i pi., 1901. onicus, the uppermost surface, the ani- 



mal pole, is traversed by definite, sharply 

 marked lines, separating areas resembling the blastomeres in a late cleavage 

 stage of Lepidosteus. The red-colored germinal* disc is further down the side 

 of the egg. The author argues that these lines are reminiscent of holoblastic 

 cleavage. It can thus be concluded that the great size of shark eggs was 

 attained before that cleavage was lost and that the yolk region of such eggs is 

 homologous with the lower pole-cells in other Ichthyopsids. a. m. c. 



, , „ ^ _ , ,, . , The author states that hairs for medico- 



London, E. S. Exammation of Hairs for 

 Medico-legal Purposes. Archiv. Sci. bio- legal examination should be mounted 

 logique St. Petersb. 7:136-157, 6 pis., dry in balsam, as preliminary treatment 



causes them to lose many characteristic 

 features. From the many species examined (39) the following conclusions are 

 reached : it is easy to distinguish between hairs of animals and other bodies of 

 similar appearances. It is easy with practice to distinguish between human 

 hair and that of lower animals ; with a consideration of all the peculiarities the 

 original site of the hair may be determined. From the appearances of the roots, 

 if several specimens are available, it is possible to determine whether the hairs 

 have fallen out or been plucked out. By the use of a polariscope a gray hair 

 may be recognized from a pale blond. With crossed nicols blond hair gives a 

 golden yellow band on a black ground, while a grey hair gives a parti-colored 

 band, the red-purple predominating. In arsenic poisoning the metal passes 

 into the hair ; this was shown by injecting arsenic into animals hypodermically 

 and testing the hair by the usual chemical methods. Control animals gave 

 negative results. a. m c. 



^, „ . ^, ^ , ^ . . , Dr. A. Noll has devised a freezing ap- 



Noll, A. New Ether Freezing Apparatus for ° 



the Microtome. Zeitschr. f. wiss. Mikr., paratus, by which the necessary cold- 

 ly * \4'~ '.44' /= H^-^ '90I- (Fr Journ. j^ggg jg obtained by the evaporation of 

 Royal Micr. Society, iio-iii, Feb., 1902. •' 



ether in a vacuum. It consists (Fig. 1) 



of a metal chamber K with two side pipes a and ^, and a bar c for fixing to the 

 microtome. The side pipes are connected by tubes s^ s^ '■, s^ joins on to a fun- 

 nel and is supplied with a stop-cock T ; jg connects with a suction apparatus /> 

 (water pump) which exhausts the air in the chamber. 



