SKETCH OF PROFESSOR HAECKEL. 109 



nal form, in internal structure, and in all vital phenomena, so remark- 

 able a mixture or combination of distinguishing animal and vegetable 

 characteristics, that it was impossible, except arbitrarily, to assign 

 them to either realm : he assigned these doubtful beings to a kingdom 

 by themselves, below and yet between the two other organic king- 

 doms, and this he called protistic. Again and again in existing forms 

 he traced development from preexisting ones. Many biologists, 

 among them Prof. Huxley, have pronounced this the most important 

 work of the kind ever published." 



In the winter of 1867-68 he delivered a series of popular lectures, 

 on the evolution doctrine in general, which were afterward amplified 

 and published under the title of " The Natural History of Creation." 

 Many editions of it have been called for, and it has been translated 

 into several languages. Darwin says of it, in the introduction to the 

 " Descent of Man : " " If this work had appeared before my essay had 

 been written, I should probably never have completed it. Almost all 

 the conclusions at which I have arrived, I find confirmed by this nat- 

 uralist, whose knowledge on many points is much fuller than mine." 

 This work will soon appear in English. 



Prof. Haeckel's most important original contribution to the doc- 

 trine of evolution has been made by the study of the sponges. Con- 

 sidering that Darwin's mode of investigation was only synthetical, 

 that is, " to prove the truth of the transmutation theory by arguments 

 from philosophy and biology, from comparative anatomy and paleon- 

 tology, by considerations of the mutual affinities of organic beings, 

 of their embryological relations, their geographical distribution, geo- 

 logical succession, etc." Prof. Haeckel aimed to establish the theory 

 by direct analytical proof. For this purpose " he has selected the 

 group of calcareous sponges, and has shown by thousands of exami- 

 nations the gradual transitions from the most simple to the most per- 

 fect sponge form." Prof. Haeckel's last considerable work is " The 

 History of the Evolution of Man," just ready for issue in Germany, 

 and a very large edition of which has been subscribed for. A trans- 

 lation of this work also will soon appear in English. 



We are indebted for the leading facts of this sketch to the excel- 

 lent notice of Haeckel in Volume VIII. of the American Cyclopaedia, 

 where the reader will find a much fuller statement of his numerous 

 contributions to biological science. 



