148 



DIVISION II. COURSE OF DEVELOPMENT OF FUNGI. 



and are at first of the same breadth as the hyphae, and the even surfaces of their 

 extremities become firmly united together, in some species when their length is 

 not yet greater than their breadth, in others, it is said, not till a later stage of their 

 development. While thus attached to one another, and while dense oily proto- 

 plasm constantly passes into them from the hyphae, they grow into bodies which 

 are broadly club-shaped towards the surface of attachment and straight or curved 

 according to the species ; the two together therefore are spindle-shaped. When they 

 have reached a certain size, which in some species may be as much as i mm., 

 the further development follows two different paths according to the species. 



In the Mucoreae (Fig. 72) and the Chaetocladieae each archicarp is divided 

 by a transverse wall into a nearly cylindrical terminal cell, the conjugating-cell 

 or gamete which remains connected with the other of the pair, and into a larger 

 portion the suspensor (c), which adjoins the gamete and continues club-shaped 

 or conical. The two gametes are at first separated from one another by their 

 original membranes which form a tolerably thick partition-wall ; but these are soon 



FIG. 72. Rhizopus nigruans, Ehr. (Mucor stoloni/er, Ehr. Sihr. myc.). Formation of a zygospore. Stages of 

 the development according to the letters, e a nearly ripe zygospore magn. 90 times. The other figures reduced 

 to about the proportion oft from larger drawings. 



dissolved, the dissolution beginning from the centre, and thus the two protoplasmic 

 bodies conjugate and coalesce into a single zygosp&re d. After conjugation 

 the zygospore still increases in volume at the expense of the protoplasm of the 

 suspensors, swells into the shape of a barrel or of a ball with its surfaces abutting on 

 the suspensors flattened, and assumes the characteristic structure which will be 

 described presently (Figs. 72 e, 71 C). During these proceedings the two gametes of 

 a pair behave in some species, as in Sporodinia, precisely alike, excepting inconstant 

 variations of form in individual plants. In other species tolerably constant dissimi- 

 larities make their appearance with the delimitation of the gametes. In Mucor 

 stolonifer (Fig. 75), where the point has been more exactly investigated, the one 

 gamete is almost always only half the height of the other ; and after conjugation the 

 suspensor belonging to the smaller gamete grows into a large stalked spherical vesicle, 

 sometimes divided again by a transverse wall, while the other retains its original size 

 and conical form. 



