NA TURE 



217 



THURSDAY, JANUARY 3, 1S95. 



BIOLOGICAL LECTURES AND ADDRESSES. 

 Biological Lectures and Addresses delivered by the late 



Arthur Milnes Marshall, M.A., M.D , D.Sc, F.R.S. 



Edited by C. F. Marshall, M.D., B.Sc, F.R.C.S. 



(London : Nutt, 1S94.) 



ANY of us remember the pleasure experienced in 

 listening to the vigorous addresses of Prof. 

 Milnes Marshall, whose sudden death, about a year 

 ago, was such a blow to biologists and to all interested 

 in the spread of scientific education. In reading them 

 now, the energy and humour of the speaker are ever 

 present in the memory, giving life to the apt illustrations 

 and clearly expressed thoughts. 



The choice of appropriate subjects for the occasion of 

 these addresses shows remarkable discrimination. It is 

 quite clear that the late Prof. Milnes Marshall believed 

 that a single address— if heard at the right point in his 

 career, and delivered with the confidence of this belief — 

 might change the whole attitude of mind with which a 

 student approached his subject. 



Lecturing to the Owens College Medical Students' 

 Debating Society, he chose as his subject '" Embryology 

 as an aid to .Anatomy." In preparing to address a class 

 of students expected to deal with, and to remember, in 

 the course of their daily work, innumerable details which 

 are as yet far from receiving a scientific interpretation, 

 he selected embryology, which " offers an explanation of 

 many otherwise completely unintelligible anatomical 

 facts"; and by the example of the development of the 

 nerves supplying the muscles of the eye, the thoughts of 

 many young anatomists may well have been turned into 

 a direction which was of the most inestimable benefit to 

 their study. 



Equal wisdom and foresight were shown in th<; selec- 

 tion of subjects for addresses to the Members of the 

 Manchester Microscopical Society, viz. "Inheritance" 

 (1888), "The Shapes and Sizes of Animals" (1889), 

 "Some Recent Developments of the Cell Theory" 

 (1890), and "Death" (1893). In the choice of these 

 subjects, and in their treatment, the Members of the 

 Society are shown that the most profound biological 

 problems are to be approached and, perhaps, solved by 

 the study of the most minute detail and the lowest forms 

 of life. The student thus made fully aware of the 

 dignity and possibilities of his subject, will not be likely 

 to forget, in the patient investigation of histological or 

 biological detail, the wide issues which are at stake. 



The subjects chosen for presentation to other audiences 

 are just as happv. Sometimes, as in "The Theory of 

 Change of Function," a difficulty in evolution by natural 

 selection is taken as the subject, and the final solution 

 given in the clearest and simplest manner. It would be 

 well if this address were widely known, for the difficulty 

 it deals with is still frequently raised, just as if no 

 explanation had ever been forthcoming. In other cases, 

 wide questions, such as "The Influence of Environ- 

 ment" or "Animal Pedigrees," form the subjects of the 

 addresses. 



NO. 1314, VOL. 51] 



The addresses abound in humorous and apt illustra- 

 tions. Thus, on p. 39, in order " to show that, even in 

 our worldly transactions, changes of environment often 

 produce not only direct and immediate changes and re- 

 adjustments, but also definite and calculable ones," he 

 gives as an example the following : — " Let (z be a mer- 

 chant, and /> his purse : the combination ab will at once 

 strike you as a natural and stable one. . . . Now let c 

 be a highwayman, and d his pistol : the combination cd 

 is again recognised as a natural and stable one. Now, 

 bring the compound ab into the presence of the com- 

 pound cd, and mark how the stability of the former is 

 shaken. . . . The several elements become rearranged 

 in a manner that finds perfect expression in the formula — 

 ab -{-cd = a -{-bed." 



Again, in order to illustrate the tendency towards re- 

 version to an ancestral condition, the card house is 

 selected — 



" The resulting structure is a far more imposing one 

 than the pack of cards when laid flat on the table, but it 

 is also an eminently unstable one, its instabilitv being 

 directly proportional to the extent to which it departs 

 from its initial condition." (p. 104.) 



"The influence of food yolk on development" is com- 

 pared to "that of capital in human undertakings" 

 (p. 224), the metaphor being worked out in an interesting 

 and amusing manner. Prof. Weismann's views on the 

 absence of death in Protozoa are illustrated on p. 273 as 

 follows : — 



" If the original Amceba be called Tom, and the pro- 

 ducts of fission Dick and Harry, the upshot of the 

 process may be expressed by saying that Tom has dis- 

 appeared without having died, while Dick and Harry 

 have come into existence without having been born. 

 Nothing has died, there is no corpse to bury, and our 

 ordinary ideas with rejjard to individuality and identitv 

 fail altogether to afford answer to the question — Where 

 is Tom at the end of the process .' " 



There are a few sentences in the addresses which 

 are perhaps capable of misconstruction. Prof. Milnes 

 Marshall appears to have hesitated to accept the belief in 

 the hereditary transmission of acquired characters, and 

 )et there are some statements which seem to imply this 

 belief. This is the case with the statements that the 

 white man and the negro have been evolved " through the 

 long-continued action of selection and environment" 

 (pp. 247 and 358), that modifications of development 

 have occurred "due chiefly to mechanical causes ' 

 (p. 316), that the "larger size of the eggs of fresh-water 

 forms appears to be dependent on the nature of the 

 environment" (p. 313), although in this case it is clearly 

 shown on the following page that environment is believed 

 to act selectively and not directly. 



The term "acquired character" is made to bear still 

 further burdens in the way of special interpretations. It 

 was unfortunate so late as 1S90 to continue to speak 

 of the distinction in development " between those 

 characters which are really historical and inherited, and 

 those which are acquired or spurious additions to the 

 record "(p. 307), or to speak of the view that Amphioxus 

 and the Cyclostomes are "degenerate animals— whose 

 simplicity is acquired a.n A deceptive rather than real and 

 ancestral." (p. 335.) 



