754 SUMMARY OF CURRENT RESEARCHES RELATING TO 



one must consider tlie peduncle to represent a second cell, but only 

 from the morphological point of view : the short forms of this pedicle 

 show this point the most clearly. Besides, this cell is elongated like 

 many vegetable cells. 



This peculiarity is also manifested by the Acinetaa. But in them 

 this organ is much more delicate, and has the appearance of a colour- 

 less thread. But notwithstanding a wall with parallel sides quite 

 distinct from the cavity is as clearly to be distinguished as in the 

 broader peduncle of Podophrya. It may be also made out that this 

 peduncle is not a tube open at the two extremities nor continuous in 

 its substance with that of the side of the theca ; it is closed at its 

 upper end as well as at the lower one, which is fixed to various 

 objects. This fact is easily determined when the cell and its shell, 

 constituting the body of the animal, are detached from their base. But 

 if this latter organ is a cell, in the general acceptation of the term, it 

 is not one in its anatomical import ; for it has at no period of its 

 existence a nucleus. 



Thus this part of the organization does not, from this point of 

 view, represent a passage in these animals from the unicellular to 

 the multicellular state, any more than it does when considered in its 

 structural details. It is an example of an additional complexity 

 imparted to the organs of unicellular beings by their non-cellular 

 parts which must bo added to the instance above cited ; that is to 

 say, to that part of the organization of a protozoan or a protophyte 

 which presents the condition of a cell are added one or more parts 

 which are also organized, but to which the idea of a cell does not 

 apply. Now, the number of these constituent parts of the economy 

 goes on increasing in proportion as the economy itself becomes more 

 complex. Also, although it is said by those who maintain that the idea 

 of the cell is sufficient to condense and sum up in itself the idea of an 

 organism, that there is nothing in anatomy outside of the study of the 

 cell or compounds formed of cells, it will be seen that, when one does 

 not even yet know what parts are cellular, much still remains to be 

 done. In particular, it will be seen that, with regard to the Protozoans 

 on the one hand, and the Protophytes on the other, we should have an 

 imperfect idea of their constitution if we were limited to the examina- 

 tion of the cell, which is its chief, but not its only factor. 



We see once more that the notion of the cell is not enough to 

 include everything in both elementary anatomy and physiology, and 

 that organisms possess other things than those which occur under the 

 form of cells. 



On the other hand, viewing life as a state of movement, and not 

 of mere equilibrium, we ought, in speaking of what is the constant 

 element of every primary form of organized substance, to term it a 

 physiological unit, just as the phrase anatomical unit is applied to 

 the form itself. In fact, every element, cellular or non-cellular, 

 represents a physiological unit from this point of view ; but it is 

 important to note that it is only among the cellular units that any are 

 found to be endowed with the properties described as belonging to 

 animal life on the one hand, and even — as occurs to some extent — 



