118 Journal of the Mitchell Society ^April 



son's work is that he has satisfactorily completed this work left 

 unfinished by Cajley, and generalized it so as to apply to the 

 complete configuration of all the lines upon each of the types 

 of the cubic surface. This volume, as expressed in a recent 

 review in Nature^ is " carried through with great earnestness, 

 and so far as possible with the simplest materials; its obvious 

 sincerity cannot fail to be inspiring to anyone who mil be at 

 pains to understand it. The author's assembling of his ma- 

 terials for the constructions which follow, and the very want 

 of useless elaboration is a proof of the independence with 

 which the author has carried out his research." 



William Cain. 



development of sponges fkom dissociated tissue cells 



In this paper- the author, Dr. H. V. Wilson, presents in 

 full detail the facts in his study of the restitution of sponges 

 from dissociated cells. Precise information as to methods is 

 also given. The larger part of the illustrations are photographs, 

 chiefly at low magnification. The latter show the sponges as 

 grown on slips of glass. As the writer mentions the sponges 

 present many points of superficial similarity to myxomycete 

 Plasmodia. It is noteworthy that the method employed has 

 proved to be one by which large numbers of sponges may be 

 easily grown. Mr. R. R. Bridgers, at the time a student of this 

 University, served as Professor Wilson's assistant and during 

 one summer carried more than a hundred sponges to a stage 

 where they were quite similar to normal sponges as one collects 

 them in Beaufort harbor. A point of particular interest is that 

 a number of Mr. Bridgers' sponges went so far as to produce 

 embryos at the end of the season. From this standpoint the 

 method seems promising for the study of the general question 

 of embryo formation in sponges and quite possibly for the ex- 

 perimental determination of the conditions under which the sex 

 elements are produced. 



It is of interest to know that other investigators have shown 

 that Professor Wilson's methods are applicable to fresh-water 



2 Bulletin of the Bureau of Fisheries, Volume XXX, 1910. 



