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RESEARCHES ON FUNGI 



regarded as diploid unless its septa were provided with clamp- 

 connexions and it exhibited the acute-angled diploid mode of 

 branching. When a large haploid mycelium was paired with a 

 small haploid mycehum, the criterion No. 5, which could be applied 



Fig. 118. — Coprinus lagopus. Hypliae at the periphery of a large diploid 

 myceUmn Hke that shown in Fig. 117, drawn witli the camera -lucida. 

 The myceliiun was grown on cleared dung-agar, and only the liyphae 

 growing at the surface of the culture inediuna have been represented. 

 A few lateral hyphae which dipped down into tlie medium are shown 

 cut off by a Une. The diploid nature of the mycelium is indicated by the 

 clamp-connexions at the septa and by the narrow-angled mode of 

 branching of the leading radial liyphae. The mycelium, as it grew older, 

 would never produce oidia. Cf. the haploid mycelium shown in Fig. 112. 

 Drawn by A. H. R. Buller and Ruth Macrae. Magnification, 88. 



without using the microscope, served as a first indication whether 

 or not the large haploid mycelium was being converted into a diploid 

 mycelium. If the aerial hyphae of the large haploid mycelium 

 became increasingly fluffy around its margin spreading away from 

 the small haploid mycelium, then the conversion of the large 

 mycelium from the haploid to the diploid phase was taking place ; 

 but, if no change of this kind could be observed, then the large 

 mycelium was not being converted from the haploid to the 



