MUCOR 245 



dense contents, and its very thin limiting wall, often bearing 

 small radiating projections. 



3. Towards the point of attachment to the stalk a clearer 

 space may be recognized in the contents ; this indicates the 

 position of the columella. 



Add a drop of water, and draw it under the cover-slip with 

 blotting-paper, watching the effect upon the sporangia : as the 

 water gains access to the sporangia, they burst suddenly, and 

 the wall may be torn to fragments so minute that it cannot be 

 recognized again. Meanwhile the contents, the swelling of 

 which caused the rupture, gradually distend, and may be 

 recognized as consisting of 



4. Numerous oval spores, with smooth walls. 



5. An intermediate mucilaginous substance which is capable 

 of swelling, and thus effects not only the bursting of the sporan- 

 gium, but also the dispersal of the spores. 



6. After the swelling and dispersal of the spores are complete, 

 there will be seen remaining a spheroidal body (the columella), 

 which is the distended septum of separation of the sporangium 

 from the gonidiophore : round its base the remains of the wall 

 of the sporangium may often be traced as a ragged fringe. 



IV. With similar precautions to those taken in the case of the 

 spores of Eurotium Aspergillus (p. 237), sow spores of Mucor 

 in a drop of a sterilized decoction of horse-dung, or of French 

 plums, or other suitable solution : the swelling and germination 

 of the spores and the formation of the branched, non-septate 

 mycelium are to be watched ; and drawings may with ad- 

 vantage be made at intervals, so as to record the progress of 

 the cultures. 



SPORODINIA GRANDIS, Link 



V. Mucor mucedo also reproduces itself by means of zygo- 

 spores, which are of such size that they may be detected with 

 the naked eye as black bodies which project slightly from the 

 substratum ; but they are not of constant occurrence, and may 

 frequently be looked for in vain. Accordingly it will be found 



