358 // 



APPENDIX 



In Toxopncustcs, however, renewed studies indicate that the facts are different {Science, /.<:.), 

 and they support in substance my original account and those of Boveri and Reinke. In this 

 material, after the same treatment, the single granule is found only as late as the early pro- 

 phase; at a later period the centre of the aster is occupied by a group (10-20) of intensely 

 stained granules suspended in a well-defined reticular "centrosphere." The latter is con- 

 siderably smaller than in my former preparations, and I have no doubt that the enormous 

 spheres shown in Fig. 37, and in my Atlas of Fertilization have been exaggerated by the 

 reagents. I do not believe, however, that the sphere itself is an artifact, and I am inclined 

 to believe that it represents a " pluri-corpuscular microcentrum," such as Heidenhain 

 describes in the case of giant-cells. 



23. P. 240, last line. There are probably various forms of nucleic acid forming a group 

 of nearly related compounds. According to the latest work of Miescher {Arch, exp. Path. 

 u. Pharm., XXXVII., '96), the formula of nucleic acid derived from the sperm-nuclei of 

 the salmon is C4oH54Ni4Oi7(P2Os)2. Miescher rinds that the sperm-nucleus does not 

 consist of pure nucleic acid, but largely of protamin nucleate, i.e. 35.56 % protamin 

 (Cie HagNgC^) combined with 60.50 % nucleic acid. 



24. P. 256, 1. 7. Conklin {Am. Nat., Jan. '97) has observed similar amoeboid changes 

 in the nuclei of intestinal epithelium in isopods; and he believes that food-granules pass 

 bodily into the nucleus. 



25. P. 278, 1. i. See Jennings {Bull. Mus. Comp. ZooL, XXX. I, '96) for a remarkable 

 account of the cleavage of the ovum of Asplanchna, in the course of which every known 

 " law " of division seems to be contradicted. 



26. P. 292, 1. 20. It is well known that leucocytosis may be induced by various chemical 

 stimuli. Thus the injection of nuclein into mammals causes active leucocytosis (Kuhman, 

 Zeit. f. Klin. Med., '95). The same result is produced by pilocarpine (Horbaczewski, 

 Ber. Wien. Akad., No. 100, '91). 



27. P. 312, 1. 32. This statement conveys a somewhat misleading impression of Hert- 

 wig's view. The " formative power pervading the entire mass " is conceived, as I under- 

 stand Hertwig, not as a unity, but is rather a resultant of the individual energies of the 

 blastomeres and is due to their interaction (Wechselwirkung). The essence of Hertwig's 

 conception is the view that every cell contains the germ of the whole and may give rise to 

 the whole or to any of its parts, according to its relation to the other cells. 



28. P. 239, 1. 29. Emery (A. A., XIII. 1-2, '97) has called attention to the fact that 

 the credit for the first discovery of this remarkable regeneration of the lens belongs to 

 Vincenzo Colucci {Mem. Acad., Bologna, '91). 



COLUMBIA UNIVERSITY, NEW YORK, 

 March, 1897. 



