24r) TllK A.MKlilTAN .MD.NTllLV [Si'i.t., 



<»n nliuost any sort of a fouiulation. On April 18, Tuesday, I 

 sot a ilry-yeast cake away umU'r a tunihlor haviiii: lirst wet the 

 yeast cake. On the foUowin^j Montlay, it was nearly covcrctl 

 with this mould. The plant also grows on j)ieiH'3 of horsc-dunjj; 

 if th«'y are kept under glass to insure that they remain moist. 

 Moisture is an indispensihle factor in tiie growth of all fungi. 

 The plant can he recognized hy th«> long gray threads termin- 

 ated with black spherical spots. I found on a piece of paper that 

 had been {-tiinding a year with Mucor on it, very iirett}' growths, 

 from the spots "vhere the spores had fallen on the paper and 

 germinated. The drawing that accom])anies this article is from 

 one of these. 



In Mucor, usually, if the specimen is well nourished, the 

 hyjihu' are not divided into cells. This makes the ])lant out to be 

 a single and very elongate cell. There are in sj)ecimens grow- 

 ing in a soft medium, like bread, a few hyplue spread ()Utl)elow 

 to form a mycelium. We must remember that the mycelium 

 is the )»art which gets the food in tlie allotment of labor to the 

 different jtarts of these plants This ])art in our sj)ecimcn looks 

 like a lot of roots. It was sjjread out on the i)aper and from it 

 drew its food so long as the paper remained moist. The aerial 

 hypha> are not branched. They arise as a single unjointed 

 tube running up to their summit on which they bear the spheri- 

 cal spore-case or "sporangium." The sporangium is a covered 

 case; really, it is a single cell in the interior of which the prf)to- 

 plasm divides up into a multitude of spores. This same result 

 is reached in Penicillium very differently. There the hyplue 

 produce a great many basidia and these tlun in their turn ]»ro- 

 duce the conidia while here the spores, which are the equiva- 

 lents of conidia, are produced by the division of the protoplasm of 

 the cell, set ajtart for that work, at once. In Penicillium a great 

 many cells unite to form the aerial hypha; here only one, to 

 form the hypha and another for the sporangium do all this ])art 

 of the work. 



The sporangium is covered witli a delicate cover which as the 

 l)lant grows older becomes elastic and finally bursts allowing 

 the spores to escape. I believe the spores are thrown out with 

 some violence, for the jiaper on the sides of the vessel was liter- 

 ally pepj)ered with their growth in every ])art. The interior of 

 the hypha under the high jmwer shows the presence of proto- 



