THE FUNGI : ASCOAIYCETES AND BASIDIOMYCETES 291 



investigated many members of this order and finally published the only 

 comprehensive monograph of these organisms. The following account 

 therefore is taken from this monograph. 



The ascospores are fusiform in shape and are enclosed in a gelatinous 

 sheath. Each spore is divided into two cells of unequal size, and the gelatinous 

 wall is particularly well developed around the larger cell which lies toward 

 the tip of the ascus before it is discharged. When this discharge takes place 

 this larger cell with the gelatinous mass attached to it comes into contact 

 with the integument of the insect and soon becomes firmly fixed thereto. 

 This constitutes the receptacle referred to above. 



The Antheridium 



At this stage (Fig. 285) the organism consists of two cells, a large basal 

 cell (i) and a smaller upper cell (2). The basal cell now cuts off a small 

 cell which becomes the foot (i.i). The upper cell meanwhile divides into 

 two cells by an oblique wall which is followed by a second similar oblique 

 septum, thus forming three cells (2.1), (2.2) and (2.3). The lowest of 

 these cells (2.1) now cuts ofl^ a wall perpendicular to the original one, 

 thus dividing the cell into a large basal cell (2.1.1) and a small apical cell 

 (2.1.2). This apical cell grows rapidly upwards pushing the cells (2.2) and 

 (2.3) to one side. These two cells now divide in the same way cutting off 

 apical cells, as may be seen in Fig. 285, forming (2.2.2) and (2.2.1) and (2.3.2) 

 and (2.3.1) respectively, while at the same time a new cell (2.4) is cut off^ at 

 the top from cell (2.3). Subsequently this cell also cuts off an apical cell 

 (2.4.2) from a basal cell (2.4.1). In addition to this the top cell (2.5) 

 remains undivided and curved downwards by the growth of the inter- 

 mediate cells. 



It will thus be seen that from the original upper cell (2) a group of five 

 antheridia are produced, from the apical cell of each of which a tiny non- 

 motile body is produced which is the male gamete or spermatium. It is a 

 naked protoplasmic body, which is liberated from the antheridium and is 

 carried passively to the female organ. 



The Ascogonium 



The ascogonium arises from the basal cell (1.2) of the original receptacle. 

 It divides first into two cells (a) and (b). The upper cell remains small and 

 forms the base of the appendage, while from the lower cell the future 

 ascogonium is formed. Cell {b) now divides into a large basal cell (b.i) 

 and a small apical cell (b.z). The latter again divides forming two cells 

 {b.2.1) and {b.2.2). The further divisions are not entirely constant and we 

 need not follow them in detail. 



The development of the ascogonium takes place by the evolution of a 

 cell mass derived from the original apical cell {b.2.1), which will now be 

 referred to as cell (c) for simplicity. This cell grows upwards and divides 



