II Some of the " Best Books " on Animal Life 357 



d'Anatomie comparie pratique (Paris, 1885-92) or in German 

 (Braunschweig) ; Prof. W. K. Brooks's Handbook of Invertebrate 

 Zoology for Laboratories and Seaside Work (Boston, 1882); Prof. 

 T. J. Parker's Zootomy (Lond., 1884) and Practical Biology 

 (Lond., 1891). 



{c) As early as 1 80 1, Bich^t had penetrated beneath the organs 

 to the tissues which compose them, and his Anatomie Ginirale is 

 the forerunner of many works on minute anatomy or histology. 

 From the comparative histology of animals by Leydig {Histologie, 

 1867) the zoological student must begin, but to follow it up he must 

 have recourse to the pages of scientific journals. As a guide in 

 microscopic work. Dr. Dallinger's new edition of Carpenter's well- 

 known work. The Microscope (Lond., 1 891) may be cited. 



(d) In 1838-39, Schwann and Schleiden, two German naturalists, 

 clearly stated a doctrine towards which investigation had been 

 gradually tending, namely, that each organism was built up of 

 cells, and originated from a fertilised egg-cell. In the establish- 

 ment of this ' ' cell-theory " the study of structure became deeper, 

 and the investigation of animal cells still becomes more and more 

 intense. To gain an appreciation of this step in analysis, the 

 student may well begin with the article " Cell " in the new edition 

 of Chambers's Encyclopcedia, and with the articles " Morphology " 

 and " Protozoa" in the Encyclopcedia Britannica. From these he 

 will discover how his studies may be deepened. 



(«) Finally, with the improvement of microscopic instruments 

 and technique, investigation has touched the bottom, as far as 

 biology is concerned, in the study of the living stuiT or protoplasm 

 itself. Again, I refer you to the articles " Protoplasm " in the 

 Encyclopcedia Britannica and in Chambers's Encyclopcedia. 



I shall not follow the history of physiology in detail, but content 

 myself with saying that (a) from the conception of a living body 

 ruled by spirits or dominated by a temperament, physiologists passed 

 to consider it (S) as an engine of living organs, then (c) as a com- 

 plex web of tissues, then (d) as a city of cells, and finally («) as a 

 whirlpool of living matter. I recommend you to read first the 

 article " Physiology" in the Encyclopcedia Britannica, then Huxley's 

 Crayfish (International Science Series), and his Elementary Text- 

 book of Physiology, then Jeffrey Bell's Comparative Anatomy and 

 Physiology and Lloyd Morgan's Animal Biology, after which you 

 may pass to larger works such as the text-books of Kirkes (new ed. , 

 1892) ; Bunge (Lond., 1890) ; Landois and Stirling, McKendrick, 

 and Foster, and to the studies on comparative physiology by 

 Krukenberg, Vergleichend-Physiologische Studien and Vortrage 

 (Heidelberg, 1882-88). 



In the above summary nothing has been said about the history 



