18 



SPORES AND THALLIDIA. 



becomes a sporangium. The increase in weight of the sporangium causes the 

 filiform stalk to bend; the sporangium bursts, and the spores, together with the 

 clear fluid in which they are suspended, issue through the rent in the sporangium 

 (c/. fig. 193^). 



In the Moulds of the family of the Mucorini the sporangia are for the most part 



Fig. 1S3.— Moulds. 



Mucor Mueedo- x40. « Longitudinal section of a sporangium of ifucor ifwcerfo; x260. « Fruit-formation in Mucor J/uc«do; 

 XlSO. * Aspergillus niger; x30. ' Longitudinal section of a sporophore of A«per(7i7ZMS Ju^er. « Fructification of /"enicit- 

 lium crustaceum (after Brefeld). ? Fruit-formation in Aspergillus (after Eidani). » Penicillium crustaceum ; x 40. 

 9 Sporophore of Penicillium crustaceum ; x 200. 



closely crowded together, but they are never walled in by a tissue or surrounded 

 by any particular envelope. They are, moreover, always separate, and have the 

 appearance of a miniature plantation. A different state of aflfairs is found in that 

 group of Fungi known as the Ascomycetes, a group which includes, amongst well- 



