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 1 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 swspensor (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 
e d 
FIG. 72. Rrizopus nigricans, Ehr. (Mucor stolontfer, Ehr. Silv. myc.). Formation of a zygospore, Stages of 
the develöpment according to the letters. e a nearly ripe zygospore magn. go times. The otfer figures reduced 
to about tite proportion of e from larger drawings. 

dissolved, the dissolution beginning from the centre, and thus the two protoplasmic 
bodies conjugate and coalesce into a single zygospore 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 ¢, 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. 72), 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. 
