286 LEAVES OF IIAKEA. 



ill a leaf of this type is not very apparent. They certainly cannot 

 be required to carry out the same function as in H. pcctinata. 

 It is, I think, understandable that such a type of idioblast cell 

 should arise in the evolution of the xerophytio type of leaf with 

 cylindrical segments from some flat xerophytic or non-xerophytic 

 fonn. If H. pectinata was evolved from the H. suaveolens type, 

 it would become necessary to explain the need for and presence of 

 the idioblast cells in H. suaveolens as being the fimt type in which 

 they appeared. I think, however, that we have here a case of 

 reversion, that is, that the type of leaf as found in H. suaveolens 

 has been evolved from that of H. pectinata. We have to imagine 

 that H. pectinata has endeavoured to return to a normal type 

 of flattened leaf whilst still retaining its xerophytic characters. 

 In so doing the idioblast cells have been retained simply as an 

 atavistic feature, and no longer function in any mechanical way. 

 Evidence of evolutionary reversion is very rare amongst plants. 

 At present I have been unable to examine the leaves of any 

 other hakeas, so perhaps this short account is incomplete. As a 

 preliminary note, however, it may be of value in showing that 

 more evolutionary connections amongst plants may be looked for. 



XOTE ON" THE I-KOWE OR NATAL KAFIR 

 MUSHROOM, SCm^LZERIl UMKOWAAN. 



By Paul A. vax der Bijl, M.A., D.Sc, F.L.S., 

 Natal Herhaiiuiii , Durban. 



Read Julii 15, 1920. 



The Kafirs are especially careful in selecting mushrooms for 

 eating, and mushroom poisoning among them is seldom heard of. 



They avoid several edible mushrooms, such as Coprinus 

 comatus (the shaggy inky cap), Letiopa proccra (the parasol mush- 

 room) and others ; and they are even very sceptical about the 

 co'mmon European mushroom — Agaricus canipestris. They, 

 ho'\\'ever, relish their " i-Kowe " — a large mushroom popularly 

 known to' Evu'opeans as the beefsteak or butter mushroom — and 

 during the season it is not uncommon to see natives return from 

 the fields for breakfast with freshly collected " i-Kowe " in their 

 hands. 



This mushroom was first named by Cooke and iMassee in 1889 

 from specimens sent by the late Dr. Medley- Wood. For the 

 specific name thej' selected Schnhjcria iim'koiraan , which they 

 were evidentlv infoiTned was the native name. 



