72 RESEARCHES ON FUNGI 



species of that genus. The protuberancy of the basidia of Bolbitius 

 flavidus, while marked, is not nearly so great as that of the longest 

 basidia of Lepiota cepaestipes, Psathyrella disseminata, and the 

 Coprini. It is no greater than that characteristic of the fruit-bodies 

 of the Panaeolus Sub-type ; and, as in Panaeolus campanulatus, it 

 just suffices to secure that each basidium shall get its top well 

 above the external walls of the paraphyses and above any wasted 

 spores that may cling to them, the result being that the sterigmata 

 and spores freely develop without mechanical hindrance. 



Various stages in the development of the basidium are to be 

 seen represented in Fig. 35. The youngest basidium, a, is non- 

 protuberant ; it next becomes fully protuberant, 6 ; it then develops 

 sterigmata, c ; then spores, d, e, f, g ; which gradually turn brown, 

 h, i, j ; and are then discharged, k ; leaving bare sterigmata, I. 

 The basidium then collapses and its end becomes concave, m, so 

 that the remains of the sterigmata, which soon dwindle to mere 

 stumps, disappear from sight in the usual manner. A few seconds 

 before the discharge of each spore a drop of fluid is excreted from 

 the spore-hilum, as in Panaeolus campanulatus, etc. This is shown 

 at k. Other general points shown in Fig. 35 are : (1) the isolation 

 of the basidia from one another by the broad paraphyses, and (2) the 

 fact that basidia with spores of about the same age are not adjacent 

 to one another but are situated relatively far apart. 



It has already been shown that, as a rule, at any given time, 

 on any one small area of the hymenium, the basidia are in all stages 

 of development so that one cannot divide them into a series of 

 successive generations. This rule, however, is not invariably kept, 

 for it sometimes happens that the basidia and paraphyses in a very 

 limited hy menial area take on a remarkably regular pattern. One 

 then perceives that the paraphyses are four-sided and arranged like 

 the squares on a chess-board, and that there is a basidium situated 

 at every point where four paraphyses meet. Moreover, the basidia 

 are divided into four distinct sets which are equal in number and 

 equally spaced, and which bring their spores to maturity in suc- 

 cession so as to form four equal and successive generations. The 

 whole arrangement is shown diagrammatically in Fig. 36, A, where 

 the squares represent the paraphyses and the circles the basidia. 



