80 LECTURES 



investigations will be so extended as to include, apart 

 from the question of distribution, exhaustive accounts of 

 the comparative morphology of all the fossil remains of 

 animals and plants that the explorations of the palaeon- 

 tologist of the future will have been so fortunate as to 

 have discovered. At the present rate of progress, which 

 in its way is quite marvelous, this will, nevertheless, en- 

 tail the labors of the hands and minds of biologists for 

 generations and ages to come. For, in these days, you 

 must understand, we can hardly be said to have mastered 

 more than an average comparative knowledge of the lead- 

 ing types of the world's flora and fauna. Much that we 

 pretend to know nowadays is gotten at by the reliance 

 we place in the general uniformity of plan and structure 

 throughout all Nature, animated and otherwise. This, 

 for the present, carries us very safely for a long ways, yet 

 every scientist fully appreciates the fact, that our knowl- 

 edge can only be real when the yet unexamined structures 

 have all been exhaustively investigated. In connection 

 with this, too, it must be remembered that a great many 

 plants still exist in as yet unexplored parts of the world 

 which have not, for that reason, come into the hands of 

 science at all. 



What I have just said of morphology applies with equal 

 truth to physiology, and what is now much of an a priori 

 nature in our knowledge in this science will become in 

 the iar distant future real and actual through exhaust- 

 ive observations upon the functions of every possible 

 tissue and organ throughout the entire range of animal 

 and plant life as now existing in the world. 

 It is believed that such a full and comparative 

 knowledge of function will, during ages to come, grow 

 and develop pari passu with the growth of our knowledge 

 of structure, and the two continually flash light adown 

 each other's paths of advancement. 



There is no structure throughout all animated Nature 

 that has received anything like the amount of anatomical 

 examination and research as has the body of man. For 

 centuries it has been the subject, the species above all 

 others, that has engaged the close attention of the 

 morphologist, physician and student. Both sexes and 

 the young of all stages have come in equally for their 

 share of it; while man's development has been passed 

 thousands of times in review by investigators stamped 

 with every shade of ability. Notwithstanding all this there 

 still remains not a little, both in the anatomy and physi- 

 ology of man, which is still within the grasp of the un- 



