*♦ 



4 



BOTAXICAL GAZETTE 



[JULY 



spore were 





the spore or several germ tubes emerging from the 

 observed. The germinating spores were attached to the cover 

 glass by allowing the water to evaporate until practically dry. 

 They were then fixed in Hemming 's fluid, dehydrated, and stained. 

 The spores were constantly binucleate (text fig. iA), and the my- 

 celium developing from them was also composed of binucleate 

 segments or segments which contained paired nuclei (text fig. iB). 



Small fragments of the tissue of the peridioles also developed 

 mycelium in the cultures which grew much more extensively. 

 Text fig. iC-I shows the characteristics of the mycelium. In 

 text fig. iC, as well as in most of the mounts obtained where the 

 protoplasmic structure could be determined, the mount was not 

 dried sufficiently to make the mycelium adhere perfectly to the 

 cover glass, so that the direction of growth does not show charac- 

 teristically. Here, also, there is a binucleate mycelium provided 

 with abundant clamp connections. The clamps appear quite con- 

 stantly in connection with the branching of the main filaments 

 as well as between the branches. Text fig. iD-I shows in outline 

 portions of a number of such filaments. Text fig. iD~G illustrates 

 the development of the clamps. Near the tip a branch turns 

 backward just above -the septum (x 1 ) and becomes united to the 

 wall just below the septum (oc 2 ) . The intervening wall is absorbed 

 (x 3 ), and a new wall is formed between the clamp and the apical 

 cell from which it arose (x 4 ). So far as I could determine, there 

 was no evidence that the formation of the clamps was associated 

 constantly w r ith nuclear divisions, as has been described by Kniep 

 (6) for certain Basidiomycetes. No mounts could be secured, 

 however, in which both walls and nuclei showed distinctly enough 

 in the same specimen to make satisfactory observations on this 

 point. Hyphal anastomoses also occur occasionally (text fig. i/). 



Mycelial strands. — As soon as growth in culture has reached 

 a few centimeters, the filaments begin to show a tendency to coalesce 

 to form mycelial strands, even upon agar media (fig. 3) and much 

 more conspicuously upon loam, etc. (figs. 4-8). As development 

 continues these strands enlarge until in some cases they become 



°-5 



mm. in diameter, as found in nature, but usually being 



40-200 fx in diameter, the size seemingly being dependent upon the 



