NITSCHE S RESEARCHES ON BRYOZOA. 2^7 



one who regards my figures of the budding of the Crisice, or 

 Diastropords, or Flustra, even without understanding the 

 Swedish language, will at once see that such an opinion 

 would be an absurdity. 



As to the theoretical difficulties he has raised (' Quart. 

 Journ.,' April, 1871, p. 157) against my theory of the 

 common-bud as belonging to the colonial life, viz. the 

 theoretical impossibility of mere individuals in community 

 contributing to this budding, these difficulties must disap- 

 pear for the truth that younger zocecia are differentiated 

 from the older ones along the whole lame germinale (D'Orb.), 

 before the latter are full-grown, and this with a continuity 

 (e. g. Diastropora) that leaves no doubt that the budding is 

 going on as a common function of the colony. It is princi- 

 pally from the Cyclostomata that this theory most easily will be 

 understood ; but even in the Chilostotnata, although there 

 the individual life is more developed, the commonness of the 

 budding is perceptible, though it gradually approaches the 

 simple budding by the uniserial forms (Eucratea, &c.). 



As to the structvire and development of the endocyst 

 (mantle), Dr. Nitsche, in the most pregnant mode, con- 

 firms my observations on Vesicularia and Membranipora, 

 and he just cites the place ("' Ofvers. Vet. Akad. Forh.,' 

 1866, p. 519), where I have described the development of 

 this structure in the same manner as he describes it himself 

 (' Zeitschr.,' 1. c, p. 453), but all that he knows of my ob- 

 servations is the notice (1. c, p. 49.3) that I should have 

 doubted of the correctness of my former description of the 

 net in the mantle. 



As to his inner layer of the endocyst, the " Spindelcell 

 schicht mit anliegenden Kornerhaufen," though I have not 

 succeeded in seeing the true " Spindelcellen," it is the same 

 layer within which I have followed the development of the 

 polypide, &c. This layer, which even Nitsche sometimes says 

 to be missing, I have not separated from the "floating cells " 

 in the perivisceral cavity, because, as anatomical features (as 

 far as 1 have seen), they pass over into each other in their 

 looser or closer aggregations ; and as to their morphological 

 significance and physiological function, they are developed ii: 

 the same manner within the perivisceral (lymphatic) fluid, 

 and seem to serve in the same manner for development or 

 nutrition. Hence the whole controversy is concerning the 

 name of that layer. 



As to the so-called " nervous system of the colony," I 

 have retained its older name, instead of giving it a new one, 

 being unable to add anything that really could give it 



