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. 1931). 



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



rig. 1B3.— Moulds. 



I Jlucor Mucedo; X40. ' Longitudinal section of a sporangium of Ifuisor JIfucedo; X360. > Fruit-fonnation in Jfucor ^uonZo; 

 xlSO. * Aspergill'm niger; x30. « Longitudinal section of a sporophore of .^sperffi^iiM »^«''. « Fruotlflcation of Penictf- 

 2mm crustaceum (after Brefeld). ' Tmit-formation in Aspergillus (after DidamX > Penicaiium crustaeeum; x40. 

 ^ SpoiophoTe of Penieilliumiyrustacewm; x200. 



.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 difierent state of affairs is found in that 

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



