72 



MANUAL OF BOTANY 



bodies described above as spermatia are not a form of the stylo- 

 gonidia, and not sexual cells at aU. In some oases they have been 



found to be capable 

 Fig. 822. of germination, pro- 



ducing a mycelium 

 without any sexual 

 fusion. 



In a few families, 

 such as the Sapro- 

 legnias, the spores are 

 not clothed with a cell- 

 wall, but are ciliated 

 free-swimming bodies. 

 They are produced in 

 great numbers inside 

 special terminal spo- 

 rangia {fig. 826). 



Fig. 8J2. Oogonia and an- 

 theridia of Achlya Ugni- 

 cola. The letters A to K 

 indicate the course of 

 development. The pro- 

 toplasm of a cell or 

 branch of a cell collects 

 into a globular form 

 A, B, and by the forma- 

 tion of a septum, D q, 

 becomes an independent 

 cell (the oogonium). 

 The protoplasm then 

 breaks up into two or 

 more parts, D, #-, e 

 (oospheres), which 



quickly become spheri- 

 cal, as seen in D, secrete 

 a cell-wall e, and be- 

 come oospores. After 



Sachs. Pig. 823. Occ- 



iioayte oi Mucor Mucedo bearing a sporangium or gonidangium. k. This is more 

 highly magnified iu the flg. to the right, m. Columella. I. Gonidia or spores. 



The sporangia or gonidangia may be produced singly or in 

 groups. In the latter case the gonidiophores which bear them may 

 be coUeoted into special receptacles which are known as pycnidia. 



