THE NEWTS STOMACH DURING DIGESTION 451 



GUY '" also has seen chromatic granules extruded through the nuclear wall, 

 which he believes to be elastic as it closes up again immediately after their 

 passage. Further A. Michel ■" has stated recently that nucleoli consist of 

 two parts, a main substance and an accessory substance. More recently 

 still A. PizoN " from his studies in ascidia (M.socialis and M.simplex) con- 

 cludes that the nucleolus during the whole ripening of the ovum throws off 

 big spherical masses of effete substance that leave the nucleus by passing 

 through its wall into the vitellus through which they are moved to the 

 peripher}' in a peculiar manner, i. e. the nucleolus in part at least is effete 

 material. 



I believe that in this animal, the nucleoli consist entirely of effete ma- 

 terial which is produced during nuclear activity, that the nucleus is capable 

 of tolerating this material in certain amount, but that when it becomes 

 excessive it is passed out into the protoplasm where it disappears. It cer- 

 tainly does not become converted directly into zymogen granules as some 

 would hâve us believe. 



I hâve shown elsewhere '' that the nucleolus of the mammalian ovum 

 should also be considered as mainly composed of effete material. 



I cannot agrée with Balbiani ' who considers the nucleolus to be a 

 sort of heart for the cell, or with those who believe that chromatin is 

 manufactured in it (Flemming ^'j Malaquin "*, etc.) or even with those who 

 maintain that chromatin elaborated elsew'here is stored up in the nucleolus 

 (Sabotta -', Labbé ''', Mingazzini -', etc.). 



I therefore agrée with Hacker" and those other observers who hold that 

 the nucleolus is entirely or at least in great part composed of effete material. 

 The changes occurring in the nucleo-hyaloplasm are also interesting. 

 When precipitated with mercuric chloride, during the resting condition, the 

 precipitate (Lanthanin granules of M. Heidenhain '") stains pale blue. As 

 activity proceeds thèse granules become more and more scanty, but just 

 after the nucleus reaches its maximum of shrinkage, the lanthanin becomes 

 very abundant and stains of a deep blue colour, which gradually gives place 

 to a beautiful lilac tint as repair goes, on finally returning to pale blue when 

 repair is complète. This dénotes that the nuclear juice undergoes chemical 

 change during nuclear activity. Strasburger ^° in 1S92 stated that the reac- 

 tion of nuclei depended upon their condition of nutrition; well nourished 

 nuclei being er3'throphile and poorly nourished ones c)-anophile. This cor- 

 responds well with what has just been stated. 



57 



