Miscellaneous. 311 



by a layer of transparent protoplasm. The external part of the 

 protoplasm of the body, which at hrst formed a simple homogeneous 

 and transparent layer without granules, becomes more and more 

 distinctly bounded, and soon presents the form of a membrane with 

 a double contour. The nucleus becomes regularly oval and also 

 surrounds itself with a membrane. 



By these changes and its increase in size the pseudofilaria finally 

 acquires the definitive form of Gregarina gigantea, and a length of as 

 much as 16 millims. 



M. van Beneden follows this description of the development of the 

 Gregarina with some very interesting general considerations upon 

 the Monera and the Monerian phase of the Gregarince. According 

 to him, if we admit that the substance of the Monera and cytodes is 

 identical with the sarcode of the Rhizopoda and the protoplasm of 

 cells, as regards pJu/sical and vital properties, we must regard it as 

 different from those bodies from a chemical point of view, since it 

 also contains the elements of the nuclear organs, which are differen- 

 tiated from it in the cell. He cousequentlj' proposes the name of 

 plasson for the constitutive substance of the hodg of the Monera and 

 cytodes. Although recognizing with him that both in the ontogenic 

 and in the phylogenic series we always, at the beginning, find this 

 plasson before meeting with cell-formations, it seems to us that the 

 necessity for this neologism has not yet made itself felt. Our 

 knowledge with regard to the nuclear formations compared with 

 protoplasm is too unsatisfactory to render it very urgent for us to 

 distinguish these substances by names destined to indicate their 

 chemical differences. Moreover, if we were to commence this course, 

 we could not stop at the nomenclature proposed by M. van Beneden ; 

 it would be necessary to have : — a first name for the living substance 

 which does not present cither nucleolus, nucleus, or enveloping mem- 

 brane ; a second for that which has already abandoned the elements 

 necessary for the formation of the nucleolus ; a third for that from 

 which have been separated the elements of a nucleolus and a nucleus, 

 bodies which M. van Beneden regards as chemically distinct (p. 146) ; 

 and a fourth for that wliich, besides these nuclear organs, has 

 furnished the elements of an enveloping membrane. This list is 

 still incomplete ; we should have to add to it, among others, the 

 protoplasm of the lepocytodes. It must be remarked, moreover, 

 that the substance to which M. van Beneden wishes to give the 

 name oi. plasson, on account of its chemical composition, is already a 

 complex substance, even, from -a histological point of view, since the 

 author recognizes in the interior of the transparent mass granules 

 of two kinds, one kind being regarded by him as nutritive, com- 

 bustible elements ; he even explains, by the presence or absence of 

 these granules, the different manner in which the movable and 

 immovable arms of the Gregarince in the amoeboid state behave. 



The ontogenic development of the Gregarina^, as M. van Beneden 

 indicates, represents in an abridged form the phylogenic develop- 

 ment of the cell. We have here an example of endogenous gene- 

 ration by the formation of the nucleus in the body of the i^seudo- 



