

19"] CURRENT LITERATURE 347 



1 



witschia and Amentales belong to the same lateral phylum, the former at its 

 base, the latter at its summit; that by comparing Welwitschia on the one hand 

 with gymnosperms and on the other with angiosperms one may obtain a rough 

 reconstruction of the characters of proangiosperms. 



The crux of this whole argument is the interpretation given to the inner, 

 micropyle-forming integument as of carpellary nature. If this is true, no other 

 testimony is needed; and if it is not true, then no other testimony can show 

 the angiosperm level. As stated in the former notice, this contention in the 

 main brings us back to the old conflict over gymnospermy. It is clear that 

 Welwitschia is a member of a reduction series, and one can imagine an open 

 ovary derived from a closed one, for there are open ovaries among angiosperms; 

 but it is not easy to imagine a reversion to such structures as archegonia, etc., 

 unless proangiosperms may have retained archegonia in stages of elimination. 



It will be interesting to note the disposition made of Gnetum and especially 

 of Ephedra in the subsequent papers. — J. M. C. 



Investigations on Coprinus. — Weir 15 reports a series of miscellaneous 



investigations on various species of Coprinus. He finds that the deliquescence 

 of these forms is brought about by the action of digestive enzymes and goes on 

 entirely without the aid of bacteria. The digestive enzymes are most abundant 

 when the fruit bodies approach maturity. The various parts of the fungus 

 show considerable differences in resistance to the action of these enzymes. 

 None of the young tissues are affected by extracts of older individuals. Parts 

 of the gills and pileus of older plants, however, are readily dissolved, while 

 the stems are not much affected. Other enzymes whose presence was shown 

 by appropriate methods are tyrosinase, peroxidase, catalase, emulsin, amidase, 

 diastase, coagulase, invertase, cytase, pectase, lipase, and rennetase. 



The rest of the paper deals mostly with questions of experimental mor- 

 phology, and more particularly with the relation between the capacity for 

 regeneration of these fungi first pointed out by Brefeld, and the degree of 

 differentiation of the regenerating tissues. It is found that in the very young 

 fruit body the power of regeneration is not localized, but that all parts are 

 capable of producing new plants from all cut surfaces. In the young cut stem, 

 pilei grow out most readily from the pith, but later, when the pith has dis- 

 appeared, the regenerating zone moves outward toward the periphery. In the 

 pileus, regeneration takes place most readily at first in the region which is to 

 become the hymenium, and later in the trama. The cuticle is not capable of 

 regeneration. Plants whose pilei were imbedded in plaster or stems whose 

 upper parts were thus imbedded, after removal of the pilei, produced new 

 outgrowths along the lower part of the stems. Attempts at grafting parts of 

 fungi on other individuals of the same species succeeded easily and gave 



15 Weir, James R., Untersuchungen iiber die Gattung Coprinus. Flora 103: 

 263-320. figs. 25. 191 1. 



