MOLDS 45 



but the name metachromatin is often used for it. 1 Some authors, among 

 whom is Arthur Meyer, believe them to consist of a combination of 

 nucleic acid, but this is a mere supposition. 



On the other hand, the role of the metachromatic corpuscles is now 

 well known. It is evident that they are reserve substances. Their 

 evolution proves it. Thus metachromatic corpuscles appear in great 

 abundance in the young asci of the higher Ascomycetes (Fig. 29, i and 2), 

 then accumulate in the cytoplasm of the epiplasm which is not 

 utilized in the formation of the ascospores, gather all around the 

 ascospores at the time of their forming (3-4), and are gradually 



FIG. 30. Conidial organ of Aspergillus niger with metachromatic corpuscles. 



absorbed by the latter in the course of their development (5). 

 They therefore furnish nourishment for the ascospores and from this 

 standpoint behave exactly like glycogen and the globules of fat 

 which are usually coexistent with them in the cytoplasm. We 

 shall see, moreover, that they undergo a similar evolution in the 

 asci of yeasts. Likewise in the conidiophores of molds, notably in 

 the fruiting heads of Aspergillus and Penicillium, the metachromatic 

 corpuscles are produced in great abundance (Figs. 30 and 31), then 

 gradually disappear as the conidia form (30, 3). Here again they 

 serve as food for the conidia. 



1 Because of the priority and more exact signification, the names metachromatic corpuscles 

 and metachromatin are preferable to the terms grains of volulin and volutin given by Arthur 

 Meyer. 



