TRANSACTIONS OF THE SECTIONS. 135 



and other pigments for staining, the resort to metallic depositions by the use of 

 osmic acid, silver and gold, and a variety of other additions to our means of pre- 

 paration have produced results of an astonishing kind, which have changed the 

 whole aspect ot histology from that which it wore when I myself first took an 

 interest in the subject. 



Leaving Histology, I shall devote the rest of my remarks to the morphology of 

 the Vertebrata. Here I am less disposed to indulge a gratidatory vein. No doubt 

 within the last dozen years we have had work to be grateful for. Worthy of a 

 prominent place in this, as in other depai'tments of anatomy, is the encyclopfedic 

 work, the ' Le9ons ' of JNIilue-Edwards, invaluable as a treasury of reference to all 

 future observers ; while the memoirs of Gegenbaur on the carpus, on the shoulder- 

 girdle, and on the skulls of Selachian fishes, and Kitchen Parker's memoirs devoted 

 to mature forms, may be taken as examples that morphological problems suggested 

 by adult comparative anatomy have not lost their attraction to men capable of 

 elaborate original research. And I the more willingly select the names of these 

 two writers, because on one subject on which they have written, the shoulder- 

 girdle, I am compelled to difier from their conclusions and to adhere rather to those 

 of Oweu, so far as the determination of the difierent elements in fishes is concerned ; 

 and by stating this (although the subject cannot be now discussed) I am enabled 

 to illustrate that the appreciation of the value of elaborate and painstaking work is 

 a matter totally distinct from agreement vnth the conclusions which may be arrived 

 at in the investigation of complicated problems, although wisdom and penetration 

 as to these must ever command admiration. 



But when one looks back on the times of Meckel and Cuvier, and on the activity 

 inspired by the speculations of the much-abused Oken, the writings of Geofii-oy 

 8t.-IIilaire, the less abstrusely speculative part of the works of Ct. C. Cams, and 

 the careful monographs of many minor writers ; when one reflects on the splendid 

 grasp of Johannes Midler, and thinks of the healthy enthusiasm created in this 

 country for a number of years by Owen's ' Archetype and Homologies of the Ver- 

 tebrate Skeleton,' and then contemplates the state of vertebrate morphology at the 

 present moment, it seems to me that its homological problems and questions of 

 theoretical interest do not attract so much attention as they did, or as they deserve. 



There can be no doubt that a great and curious influence has been exercised on 

 morphology by the rise of the doctrine of the origin of species by natural selection. 

 Attention has been thereby directed strongly for a number of years to varieties ; 

 and probably it is to this doctrine that we owe the larger number of observations 

 made on variations of muscles, nerves, and other structures. Particularly elaborate 

 have been the records of muscular variations, very praiseworthy, interesting to the 

 recorders, very dry to most other people, and hitherto, so far as I know, bari'en 

 cnouo'h of any general conclusions. So much the more credit is due to those 

 who have worked steadily in faith that beauty will emerge to gild their results 

 some day. 



But the doctrine of Natural Selection has had a further effect in anatomical 

 study, aiding the reaction against the search for internal laws or plans regulating 

 the "evolution of structures, and directing attention to the modifying influences of 

 external agencies. This effect has happened naturally enough, but it has been far 

 from just ; rather is it a pendulum-like swing to another extreme from what had 

 previously been indulged in. The doctrine of natural selection starts with the 

 recoo'uition of an internal formative force which is hereditary ; and in the develop- 

 ment of the doctrine, the limits of hereditary resemblance have been greatly studied; 

 and further, it will be observed that one of the fundamentals of the doctrine is, 

 that the formative force alters its character gi-aduallj' and permanently when traced 

 from generation to generation in great tracts of time. Now I am not going to enter 

 on a threadbare discussion of the origin of species in this company ; suffice it to 

 sav that, while the existence and extensive operation of such a thing as natural 

 selection seems to have been convincingly proved, it is a very different thing to 

 allege that it has been the sole, or even the principal agent in producing the evolu- 

 tions of living forms on the face of the earth. So far as Anatomy is concerned, it 

 is a secondary matter whether the link between the members of the evolving hosts 

 of life have been genetic or not. But I wish to point out that, even pushing the 



