146 



BOTANY. 



cells is now absorbed^ and their protoplasmic contents unite 

 into one common mass {d) ; the last stage of the process is 



«/ 



Fig. 76.— Conjugation of a Black Mould, a, two hyplise near each other, 

 and sending out short lateral tubes or branches, which come in contact ; 

 jb, the branches grown larger ; c, the formation of a partition near the 

 end of each branch ; < absorption of the wall between the two branches, 

 and the consequent union of the protoplasm of the end cells; e, resting 

 spore fully formed, e magnified 90 times, the others nearly the same. 



the secretion of a thick wall around the new mass, thus 

 forming a zygospore (e). 



260. The resting spore does not germinate until it has 

 undergone desiccation, and has experienced a certain period 

 of rest, when, if placed in a moist atmosphere, it sends out 

 hjrphse which bear spore-cases. Resting spores appear never 

 to form a mycelium : that is always the result of the 

 growth of the spores from the spore-cases. 



261. The Insect-fungi (JEntomopMlwracece) are well repre- 

 sented by the Fly-fungus (Entomophthora muscse), which 

 in the autumn is so destructive to house-flies. It consists 

 of small tubular cells which grow in the moist tissues of 

 the fly, and at last pierce the skin, producing minute 

 terminal spores, which give the fly a powdery appearance. 



