492 



EDWARD A. BURT ON A 



The inflated hyphae do not wholly compose the fundament of the wall of the stipe; 

 small bundles of fine hyphae b are also present but cannot be traced long distances. These 

 uninflated hyphae are undoubtedly of medullary origin, as they closely resemble the 

 medullary hyphae of the main cavity of the stipe, and, as stated in a former place, similar 

 bundles of hyphae pass from the medullary portion into the wall of the stipe near its 

 base. The inflated hyphae seem to occupy the spaces between the bundles of uninflated 

 medullary hyphae in the fundament of the stipe. 



The stipe seems to be composed in part of tissue of medullary origin, and in part of 

 tissue of cortical origin. Later stages of the egg show that the medullary tissue of 

 the wall becomes the gelatinous tissue of the chambers and finally disappears, while 

 the inflated hyphae of cortical origin differentiate further into pseudoparenchyma. 



The arms of the receptaculum are borne upon the upper end of the wall of the stipe. 

 In this stage of their development, they consist of six large masses of longitudinally 

 running hyphae (a', Figs. 14-17) passing upward from the fundament of the wall. In 

 the lower part of each mass, the tissue is very dense and seems to consist of both the 

 medullary and cortical tissues of the stipe wall but with the medullary hyphae collecting 

 into the centre of the mass. Further up the hyphae of the mass seem to be wholly 

 of medullary nature. Each of these masses is the fundament of an arm and lies in a 

 V-shaped cavity extending upward along the surface of the gleba (Figs. 14-17). The 

 arm is in contact with the supporting tissue of the gleba near the lower end — at about 

 the region of the future dome ; but 1 cannot detect any hyphae passing from the one 

 structure into the other here. 



The arms arise at the inner edges of the cortical plates (Figs. 16-17). Hyphae from 

 these plates cross the narrow separating space and come into contact with the 

 fundament of arms. I am inclined to think that these hyphae merely reach the 

 fundament and do not enter it, and that we have here; for this part of the arm, 

 the first penetration of the cortical tissue into and across the narrow surrounding 

 space which this tissue takes full possession of later on and in which it builds up 

 the wall of the arm. 



The surface of the cavities in which the arms lie is lined by a palisade-like layer of 

 cells closely packed together, which stain deeply with the carmine. They are the swollen 

 ends of branches given off by the spreading hyphae of the medullary system. This 

 layer of cells is the young hymenium (Ji, Figs. 14-17), and the swollen cells are the 

 young basidia. This hymenial layer is thrown into a series of folds which, judging from 

 serial cross sections, extend principally in a longitudinal direction and have their hollows 

 directed somewhat centripetally in between the radiately spreading hyphae of the gleba 



