222 SCIENCE PROGRESS. 



cussion. Different groups of albuminoids and gelatoids 

 yield different products; thus, gelatin, etc., bases and 

 aliphatic amido-acids ; peptones, etc., bases, aliphatic and 

 aromatic amido-acids ; and proteins containing sulphur give 

 rise to the same substances as peptones, but also to sulphur- 

 compounds. The protamines are distinguished through 

 yielding only bases. 



Proteids yield albuminoids and various other substances 

 on hydrolysis ; of these, nuclei'ns yield the purine-bases 

 (hypoxanthin, etc.) and nucleinic and thyminic acids. 



The nuclei'ns and nucleoproteids are characteristic con- 

 stituents of nucleoplasm generally, and protamines of that 

 of spermatozoa, whereas in plants the albuminoids and cer- 

 tain gelatoids are chiefly found in the cytoplasm. 



The occurrence of asparagin in germinating seeds and 

 seedlings has been long known. It was first discovered by 

 Vauquelin and Robiquet (1805) in the shoots of Asparagus 

 officinalis ; in 1858 Th. Hartig ascribed to it a general dis- 

 tribution in plants, as did also Boussingault, which statement 

 has been since amply confirmed. 1 The former also regarded 

 it as the form in which the metastasis of proteins is effected. 

 In 1872 Pfeffer opposed the view of its general distribution, 

 affirming that it was only produced during germination ; 

 he too supposed it to be the metastatic form of reserve- 

 proteins. This view would seem to obtain general accep- 

 tance among phytologists of to-day, although it has long 

 been refuted, through the works of E. Schulze and his 

 collaborators, in the form in which it was then promulgated 

 by Pfeffer. 2 



Von Gorup-Besanez was the first to show that amido- 

 compounds other than asparagin occur in etiolated seedlings 

 of Vicia saliva, and his results have been confirmed and 

 extended, a whole series of nitrogenous substances having 

 been discovered that can be regarded as products of 

 proteohydrolysis during germination. The observations 

 have been chiefly made on etiolated plants, because more 



1 For literature on asparagin previous to 1882, see Die Pflanzenstoffe, 

 Husemann & Hilger, Berlin, 1882, p. 264. 



2 Pfeffer does not now retain his old opinion. 



