114 THE AMERICAN MONTHLY [June, 



sessed by the lower animals ; or, to put this in another way, that the very 

 organs which are highest are the most open to disease attacks and yield most 

 easily. We cannot repeat the evidence adduced to prove this most interest- 

 ing statement of the result of his observation, but we notice at once the cause 

 which is assigned for the fact. He seeks to explain it by reference to a princi- 

 ple which he calls physiological reversion, and to account for the greater vitality 

 of parts common to higher and lower animals by reference to the supposition 

 that these have been used longest in the development of the race and hence 

 are strongest. Thus he brings the facts into harmony with Darwin's princi- 

 ple of evolution. He goes further and shows that these facts are not readily 

 explained upon any other supposition. Thus, for a single instance, in death 

 of the heart of the turtle, as of all cold-blooded animals, as well as the mam- 

 mals, the various parts always die in a certain order, and the ones last to ap- 

 pear are the ones which are first to die. Upon the Darwinian hypothesis it 

 is intelligible why the youngest part of the organism — the one latest to ap- 

 pear in the line of descent — should be weakest and least vital, and it is not in 

 the least so upon any other. 



We have space here only to point to this article and to the line of obser- 

 vation and study which it suggests, for the twofold purpose of showing, 

 firstly, to the physicians among our readers one way in which they may util- 

 ize the results of their very numerous opportunities for observation, namely, 

 by contributing what will prove or will disprove the principle set forth ; and, 

 secondly, of showing, with regard to Darwin's theory, how vei-y far-reaching 

 it is, and how it fits with facts drawn from the greatest variety of sources and 

 harmonizes them all. 



o 



A good manual of histology. — We have received from time to time 

 inquiries for a good illustrated book, treating the topic of mammalian Nor- 

 mal Histology, and one which shall not be too expensive. When this ques- 

 tion came up three months ago in an inquiry from a correspondent, we were 

 forced to say that the book for a beginner to use alone, which contained good 

 figui'es and did not cost too much, was not in existence. In spite of the 

 numerous histologies it seemed to us that the requirement was not met. We 

 were therefore heartily pleased to find in the work recently published by Dr. 

 M. N. Miller, of the Loomis Laboratory in New York, a book which seemed 

 preciseh' the thing to put into the hands of elementary histologists in classes, 

 or to recommend to anyone desiring to initiate himself into the very difficult 

 art of unraveling the structure of an organ from sections of that organ. The 

 author's admirable plan is first to state clearly the structure of the organ and 

 then to give students the detailed study of a section. For a beginner, the 

 chasm from a section to the intelligent comprehension of the place of that 

 section in the oi'gan of which it forms a part, and the step thence to an un- 

 derstanding of the actual structure, is enormous and one which he only learns 

 to bridge by slow degrees. We have had this fact demonstrated a hundred 

 times, and have found very bright students who only gradually comprehended 

 what thev were about when they were studying a section. Dr. Miller's plan 

 of giving vis-a-vis a study of the organ of the section receives our hearty 

 sanction, with perhaps the very slight reservation that we prefer for the edu- 

 cational value of the study to have the section study come first. One who 

 has drawn much can readily appreciate the patience and labor spent upon the 

 illustrations which add so very much to the usefulness of the volume. 



Correction. — On page 29 of the present volume, February number, 

 ' grns,' in the sixth, seventh, and tenth lines, should read grms. 



