92 



SCIENCE 



[N. S. Vol. XUil. No. 1072 



fact we offer an interpretation. Since the pictures 

 admit of different interpretations they must be ex- 

 amined in the light of the physical properties of 

 protoplasm. To have perceived and applied this 

 postulate is the unperishable contribution of 

 Biitschli. 



Accordingly nucleus and protoplasm are 

 thoroughly examined in their physical and 

 chemical relations, and the manifold structural 

 forms assumed under the microscope are par- 

 tially explained by considering protoplasm a 

 very soft gel, near the critical condition. 

 " Under various abnormal or perhaps physio- 

 logical conditions it may wholly or in part 

 become a sol." 



Two lectures are devoted to cell division, and 

 like all other parts of the book, they are illus- 

 trated with large, clear, beautifully executed 

 figures, derived from many sources. Collect- 

 ively they suggest faultless technique and tlie 

 clearest of objectives. The account of mitosis 

 imparts the fascination which this process 

 still holds upon the lecturer through its inher- 

 ent mystery, and the subject is left with the 

 following characteristic conclusion: 



Why the number of chromosomes and their size 

 are so very different in closely related species or 

 races; why specially in the seminal cells of one 

 representative of the eyelostomes (Myxine) pecu- 

 liarly formed rod-shaped centrosomes appear; why 

 the centrosomes of a particular annelid {Bhyncliel- 

 mis) attain enormous, macroscopically visible di- 

 mensions, etc.; these all are problems the rational 

 explanation of which can not be hoped for in the 

 years within sight. 



The course continues with a consideration of 

 the following themes : Growth ; the substratum 

 of inheritance; shape and structure; the his- 

 tology of metabolism; change of form and 

 motion; the nervous system; and finally, the 

 possibility of establishing histological laws. 

 Each of these subjects is treated in one or 

 more lectures, with freshness and originality. 

 The two lectures on " shape and structure " 

 state that the adult is characterized by rela- 

 tively stabile weight and fixed shape, and this 

 condition is attributed to " the high degree of 

 elasticity in the adult organism as contrasted 

 with the plasticity of embryonic stages." The 

 structures accounting for these characteristics 



of the adult are then considered — epithelium 

 and its modifications in the first lecture, with 

 the conclusion that " in maintaining the 

 typical shape of the organism, epithelial tissue 

 as such plays a subordinate role " ; and con- 

 nective tissue, with cartilage and bone, in the 

 second lecture. 



As a whole the lectures are to be highly 

 commended. Their unsolved riddles may per- 

 haps suggest to others, as to the reviewer, 

 the difficulties of Carlyle's Teufelsdrockh, but 

 much is in store for the English readers who 

 '' accompany him through all his speculations." 

 Of inconsistencies we have noted only one, and 

 can not decide which of the following propo- 

 sitions is correct : 



Histological investigation is seldom or only ex- 

 ceptionally able to take the lead over other methods 

 of investigation as a pioneer in unknown lands 



(p. 11). 



Histology belongs essentially to the sciences of 

 discovery, so that histological discoveries have 

 often, or very generally, the same exploratory 

 character as the voyages of the early mariners 

 (p. 4). 



Eeedeeio T. Lewis 



Flies in Relation to Disease — Bloodsucking 



Flies. By Edward Hustdle, B.A., Ph.D. 



Cambridge University Press, 1914. 



This volume is one of the Cambridge Public 

 Health series and complements the recent work 

 on flies in relation to disease by Dr. G. S. 

 Graham-Smith. It was written in collabora- 

 tion with the distinguished investigator. Major 

 S. E. Christophers, who, for reasons stated in 

 the preface, did not consent to appear as joint 

 author. In its preparation the author was also 

 guided by Professor G. E. H. NuttaU. It is 

 therefore to be supposed that it measures up 

 to the standard set by the noted Quick Pro- 

 fessor of Protozoology in Cambridge Univer- 

 sity. The reader will find as he proceeds 

 through the work that this is the case. 



Dr. Hindle's volume deals with the most 

 important field in medical entomology at tha 

 present time as its scope includes the treatment 

 of species transmitting such important mal- 

 adies as malaria, yellow fever, sleeping sick- 

 ness and others. In this field much activity 



