342 PROCEEDINGS OP THE AMERICAN ACADEMY. 



are not secondary connections, but primary, dating from the time when 

 the embryo was a unicellular structure." Hence Spencer maintains 

 that " the alleged independence of the reproductive cells does not 

 exist." Thus the soma is a "continuous mass of vacuolated proto- 

 plasm, and the reproductive cells are nothing more than portions of 

 it separated some little time before they are required to perform their 

 functions." 



In his " Monograph of the Development of Peripatus Capensis," 

 Mr. Adam Sedgwick, F. R. S., Reader in Animal Morphology at 

 Cambridge, writes as follows : — 



"All the cells of the ovum, ectodermal as well as endodermal, are 

 connected together by a fine protoplasmic reticulum." (p. 41.) 



" The continuity of the various cells of the segmenting ovum is 

 primary, and not secondary ; i. e. in the cleavage the segments do not 

 completely separate from one another. But are we justified in speak- 

 ing of cells at all in this case? The fully segmented ovum is a syncy- 

 tium, and there are not and have not been at any stage cell limits." 

 (p. 41.) 



He then states in his letter to Mr. Spencer : — 



" It is becoming more and more clear every day that the cells com- 

 posing the tissues of animals are not isolated units, but that they are 

 connected with one another. I need only refer to the connection 

 known to exist between connective tissue cells, cartilage cells, epithe- 

 lial cells, etc. And not only may the cells of one tissue be continuous 

 with each other, but they may also be continuous with the cells of other 

 tissues." (pp. 47, 48). 



" Finally, if the protoplasm of the body is primitively a syncytium, 

 and the ovum until maturity a part of that syncytium, the separation 

 of the generative products does not differ essentially from the internal 

 gemmation of a Protozoon, and the inheritance by the offspring of 

 peculiarities first appearing in the parent, though not explained, is ren- 

 dered less mysterious ; for the protoplasm of the whole body being 

 continuous, change in the molecular constitution of any part of it 

 would naturally be expected to spread, in time, through the whole 

 mass." (p. 49.) 



" Mr. Sedgwick's subsequent investigations confirm these conclu- 

 sions. In a letter of December 27, 1892, passages which he allows 

 me to publish run as follows : — 



'• ' All the embryological studies that I have made since that to 

 which you refer confirm me more and more in the view that the con- 

 nections between the cells of adults are not secondary connections, 



