MYCELIUM 



17 



branches of the mycelium approach each other until they touch 

 at their apices. The branches swell and become club-shaped, 

 including a rich store of protoplasm. At length the upper 

 portion of each club is cut off by a transverse septum, and the 

 two apical segments are fused into a globose body, the walls at 

 the point of contact being dissolved. Thus we have two thick 

 supporters, with a globose body suspended between them, which 

 is to become the zygospore, resulting from the conjugation and 

 coalition of the club-shaped branches (Fig. 4). The succeeding 

 steps need not be detailed ; the zygospore acquires a thick outer 

 coat, and then becomes a resting spore, which only germinates 

 after a period of rest. The same mycelium therefore produces 



Fia. 4. — Zygospore of Mucor in course of formation. After De 



erect carpophores, or couidiophores, surmounted by an inflated 

 vesicle containing conidia, an asexual generation, and also pairs 

 of nearly sessile branches, which collide and form a zygospore 

 between them, a sexual generation. Similarly, in other families 

 the two kinds of reproduction are developed, asexual and sexual, 

 from different parts of the same mycelium, but not precisely 

 in the same way, yet the details do not affect the mycelium 

 greatly, except in the family to be presently alluded to. 



The Entomophthoraccac^ are those Fungi which are parasitic 

 and destructive to insects, including the ordinary fly mould, 



' The Enlomophthorcac of the United States, by Roland Thaxter, 1888, 

 Boston, U.S. 



