TRANSACTIONS OF SECTION D. — PRESIDENTIAL ADDRESS. 403 



Section D.— ZOOLOGY. 



President of the Section: Professor E. W. MacBride, 

 M.A., D.Sc, F.R.S. 



WEDNESDAY, SEPTEMBER 6. 

 The President delivered the following Address : — 



The British Association meets for the third time in the midst of a great 

 European war, which is taxing to their utmost all the resources of the Empire, 

 although we may express the confident hope that these resources will in the 

 future prove themselves as adequate to the strain put on them as they have 

 done in the past. All of us are agreed that our country has entered into this 

 conflict with clean hands, and is striving to attain high and noble aims ; but 

 many of us tliink that the attainment of those aims has been to a considerable 

 extent hindered by a neglect on the part of our rulers and organisers to take 

 advantage of the results obtained by scientific research, and also by their neglect 

 to provide adequate means for the continuance of that research. Hence the 

 Organising Committee of the Section has very wisely sought to encourage the 

 production at this meeting of papers setting forth those results of zoological 

 research which have either a direct economic value as bearing on the rearing 

 of useful animals, or an indirect economic one as teaching us how to combat 

 harmful parasites both of animals and man. But we must never forget that 

 whilst the justification of a science in the long run — at any rate in the eyes 

 of the many — may reside in the value of its applications, yet the first condition 

 of its assured progress is the resolute adherence to the investigation of its 

 underlying laws ; and surely of all these laws the most fundamental in the case 

 of biology are the laws of inheritance. These laws, as we are all aware, have 

 been the subject of the most intensive research, especially during the last sixteen 

 years. In these researches, however, the method which has been almost ex- 

 clusively employed has been that of selective mating between different strains, 

 and attention has been too exclusively focussed on the adult characters of the 

 offspring. Another set of researches which may eventually throw a good deal 

 of light on the laws of inheritance have been going on simultaneously with the 

 experiments on cross-breeding. These researches have had as their object the 

 determination of the laws governing the development of the germ into the 

 adult organism, and researches of this kind are generally denoted by the term 

 Experimental Embryology. Even in this time of storm and stress, it seemed 

 to me to be not inappropriate if I were to endeavour in a necessarily brief 

 sketch to take stock of the positive results which have been gained as the 

 harvest of thirty years' work in this branch of zoology. 



The founder of the science may be said to be the German anatomist His, 

 who in 1874 published a small volume entitled ' Unsere Korperform und das 

 physiologische Problem ihrer Entstehung,' in which he defined the scope of the 

 new science and distinguished between what he called the physiological and the 

 phylogenetic interpretations of embryology. He says : ' In the whole series of 

 phases which a developing organism traverses, each previous phase is the 

 necessary preparation for the succeeding one,' and, further, ' The physiological 

 explanation of the forms of the bodies of animals, and the investigation of 



D D a 



