22 president's address. 



between the two layers, as was supposed twenty five years ago by 

 Haeckel and Gegenbaur and their pupils, but by a pouching of the 

 enteron to form one or more cavities in which the reproductive cells 

 should develop — pouchings which became nipped off from tlie cavity of 

 their origin, and formed thus the independent coelom. The animals so 

 provided are the Coelomoccela (as opposed to the Enteroccela), and com- 

 prise all animals above the polyps, jelly-fish, corals, and sea-anemones. 

 It has been established in these twenty-five years that the cojlom is a 

 definite structural unit of the higher groups, and that outgrowths from 

 it to the exterior (coelomoducts) form the genital passages, and may 

 become renal excretory organs also. The vascular system has not, as it 

 was formerly supposed to have, any connection of origin with the ccelom, 

 but is independent of it, in origin and development, as also are the 

 primitive and superficial renal tubes known as nephridia. These general 

 statements seem to me to cover the most important advance in the 

 general morphology of animals which we owe to embryological research in 

 the past quarter of a century.' 



Before leaving the subject of animal morphology I must apologise for 

 my inability to give space and time to a consideration of the growing 

 and important science of anthropology, which ranges from the history of 

 human institutions and language to the earliest prehistoric bones and 

 implements. Let me therefore note here the discovery of the cranial 

 dome of Fitltecanthropiis in a river gravel in Java — undoubtedly the most 

 ape-like of human remains, and of great age ; and, further, the Eoliths of 

 Prestwich, in the human authorship of which I am inclined to believe, 

 though I should be sorry to say the same of all the broken flints to which 

 the name ' Eolith ' has been applied. The systematic investigation and 

 record of savage races have taken on a new and scientific character. Such 

 work as Baldwin Spencer's and Haddon's in Australasia furnish examples 

 of what is being done in this way. 



Physiology of Plants and Animals. — Since I have only time to pick 

 the most important advances in each subject for brief mention, I nmst 

 signalise in regard to the physiology of plants the better understanding 

 of the function of leaf- green or chlorophyll due to Pringsheim and to the 

 Russian Timiriaseft', the new facts as to the activity of stomata in 

 transpiration discovered by Horace Brown, and the fixation of free 

 nitrogen by living organisms in the soil and by organisms (Bacillus 

 radicola) parasitic in the rootlets of leguminous plants, which thus benefit 

 by a supply of nitrogenous compounds which they can assimilate. 



Great progress in the knowledge of the chemistry of the living cells 

 or protoplasm of both plants and animals has been made by the dis- 

 covery of the fact that ferments or enzymes are not only secreted 

 externally by cells, but exist active and preformed inside cells. Biichner's 

 final conquest of the secret of the yeast-cell by heroic mechanical methods — 



' See the introfluction to Part II. of a Treatiso on Zoolocr}'. E<1itcil by E. Ifiy 

 Lankesler (London : A. & C. Bl.^ck). 



