312 American Quarterly Microscopical Journal. 



In the case of living-adult forms there are, and always will be, 

 breaks in the chain connecting unlike forms — wide chasms to be 

 bridged by the exercise of reason and supposition. 



When, however, we study the development of these organisms 

 from their first appearance on the field of existence as moners, 

 mere particles of protoplasmic matter of microscopic size, and 

 follow them through every stage of growth, we reach conclusions, 

 which are intelligible in the light of such knowledge of sequence 

 and relation, as only investigations of this kind can give. For 

 this reason the work of Hackel cannot be too highly valued, and 

 is sure to be a lasting monument to his name. 



It is not our purpose to review the work before us, but rather 

 to briefly present the salient features of Hackel's system of reason- 

 ing. We will not, therefore, speak of the many original thinkers 

 and students who preceded or were contemporaneous with him, 

 and whose labors contributed not a little to the ready apprecia- 

 tion of his work. Among these were (lothe, Lamarck and Dar- 

 win, each of whom, and especially Lamarck, foresaw the ultimate 

 logical conclusion and boldly proclaimed it long before the world 

 was ready to accept it. 



To understand Hackel's position, our studies must commence 

 with the very beginnings of life. To him the moner represents 

 the lowest form of organic structure. Between the moner and the 

 inorganic world, there must be some bond of connection ; for the 

 completeness of this theory requires that, at some time in the world's 

 history, life, in its simplest form, must have sprung spontaneously 

 from non-living matter. He has made no effort to explain the 

 process, nor to observe its repetition. Although the elaborate 

 experiments of Dr. Bastian have failed to indicate the proper 

 conditions under which this transformation of the inorganic into 

 the living can take place, future researches may establish this 

 hypothesis upon a basis of fact. 



Assuming then, as Hackel does, that spontaneous generation 

 has produced even a single particle of living protoplasm, the 

 entire monistic scheme of development, including man, becomes 

 complete. 



The fundamental idea of Hackel's school is, that all animals in 

 the course of their development from the germinal cell, pass 

 through various stages of existence which afford us a perfect 

 history of the process of their slow evolution from simpler forms. 

 At numerous points, along the stem which leads directly from the 



