GENESIS OF MAN. 29 



two distinct cells. Each of these then goes through with the same 

 process of nutrition and division, and so on. 



But besides these two essential phenomena, which are common 

 to all life, whether animal or vegetable, the cell performs two other 

 truly animal functions. It possesses the power of locomotion, and 

 the faculty of sensation. Cells with caudal appendages; called 

 lash-cells (Geiss else lien), have acquired that form in consequence of 

 their independent activities in their liquid medium. Various other 

 forms are traceable to similar causes. As a proof of the posses- 

 sion by cells of a faculty of sensation, we have only to consider 

 the efforts of various kinds to obtain their food. Some are actu- 

 ally carnivorous, and show a certain degree of dexterity in captur- 

 ing their prey. They are, therefore, not only capable of feeling, 

 but, in a qualified sense, of thinking and of reasoning. 



There is no essential difference between the sperm-cells and 

 germ-cells of higher animals, and the simple cells of which many 

 lower animals consist, and beyond which they never advance. We 

 can only say that among the infinitely varied forms of life we find 

 that while most creatures have developed into highly compound 

 states, and only revert to the original unicellular condition at the 

 beginning of each individual's existence, there are still many crea- 

 tures that never progress beyond this primordial stage, and whose 

 entire existence is passed in the form and condition of simple cells. 8 

 Among such creatures may be named the Amoebae, the Gregarinae, 

 the Infusoria, etc. These animals, as well as those which consist 

 simply of an accumulation or aggregation of cells, such as the 

 Labry intitule ae, etc., and which form the second stage of develop- 

 ment, never rising above the cellular condition, are classed by 

 Haeckel, together with his Planaeada, in a grand division or depart- 

 ment by themselves, and called Protozoa. A further ground for 

 this classification will be seen later. 



According to the fundamental biogenetic law above stated, the 

 cell must be the primordial form out of which all more highl) r 

 organized beings, including man, have developed, since it is the 

 original stage of their ontogenetic development. And as there 

 still exist unicellular beings resembling the sperm-cells and the 



8 A complete description, both popular and systematic, of all the unicellular organ- 

 isms known to exist, was published by Prof. Haeckel in 1878, entitled Das Protisten- 

 reick, of which he has kindly sent the writer a copy. 



