It^onal ffitgtitution of Creat iUvifattt. 



WEEKLY EVENING MEETING, 



Friday, May 25, 1883. "^^^-^T^^^^ 

 William Spottiswoodb, Esq. M.A. D.C.L. Pres. R.S. 

 Vice-President in the Chair. 



Professor W. H. Flower, LL.D. F.E.S. P.Z.S. &c. 



On Wliales, Past and Present, and their Probable Origin, 



Few natural groups present so many remarkable, very obvious, and 

 easily appreciated illustrations of several of the most important 

 general laws which appear to have determined the structure of animal 

 bodies, as those selected for my lecture this evening. We shall find 

 the effects of the two opposing forces — that of heredity or conforma- 

 tion to ancestral characters, and that of adaptation to changed en- 

 vironment, whether brought about by the method of natural selection 

 or otherwise — distinctly written in almost every part of their structure. 

 Scarcely anywhere in the animal kingdom do we see so many cases of 

 the persistence of rudimentary and apparently useless organs, those 

 marvellous and suggestive phenomena which at one time seemed 

 hopeless enigmas, causing despair to those who tried to unravel their 

 meaning, looked upon as mere will-of-the-wisps, but now eagerly 

 welcomed as beacons of true light, casting illuminating beams upon 

 the dark and otherwise impenetrable paths through which the 

 organism has travelled on its way to reach the goal of its present 

 condition of existence. 



It is chiefly to these rudimentary organs of the Cetacea and to 

 what we may learn from them that I propose to call your attention. 

 In each case the question may well be asked, granted that they are, 

 as they appear to be, useless, or nearly so, to their present possessors, 

 insignificant, imperfect, in fact rudimentary, as compared with the 

 corresponding or homologous parts of other animals, are they sur- 

 vivals, remnants of a past condition, become useless owing to change 

 of circumstances and environment, and undergoing the process of 

 gradual degeneration, preparatory to their final removal from an 

 organism to which they are only, in however small a degree, an incum- 

 brance, or are they incipient structures, beginnings of what may in 

 future become functional and important parts of the economy ? These 

 questions will call for an attempt at least at solution in each case as 

 we proceed. 



Before entering upon details, it will be necessary to give some 

 general idea of the position, limits, and principal modifications of the 

 group of animals from which the special illustrations will be drawn. 

 The term " whale " is commonly but vaguely applied to all the larger 



