THK (J EX US MUCUH. 71 



Limit; Miicor roripnhih I , i-.\;miiiied by Lichtheim. and wliicli '\n 

 pioliiiltly iiltMiticjil with Limit's Mitnn' rurtfinnxun, siiliMMjiU'iitlv 

 also imiiifd Ji'/ti.:oputi raniutiiin ; liiially Siehemnaim'K Mwor itepta- 

 ttts, which is jHM-haps the sjiine iis Miimr rai'ttinmuf. Thes*^ patlio- 

 geiiic sjn'cifs have all het*n tried on wariii-blofMled uniiiialK, and 

 therefore thrive at iiu-ultatiuii temperature. 



§ 236." The Genus Mucor 



was estjxblished by Mieheli as far baek as ijjc). l)urinj; the 

 suceeefliiig 140 years it received attention at the hands of 

 a larj^'e niunber of workers, and a considerable nundter of 

 specie.s have been described foi- the nio.st j>ait ini|terfectlv. 

 The species of this genus may be divideil into three groups. 

 One of tln'iii comprises all the species with unbranched spor- 

 angiophores, the cinef representjitive ijciiig Mtfn man do. with 

 which is associated .1/. iiiifi7(('/i7ieuf, itc. The species of the 

 .second group may exhil)it clustered branchings of tlie sporangio- 

 phores ; they inchule Mucor raciiiiosiDf, M. luertiia, M. tenuis, 

 M. fiaiiilix, M. rori/iii/>i/i'i% and M. j'iixi//ii.<. Finally, the char- 

 acteri.stic featiu-e of the third group is a more or le.ss decided 

 S3rmpodial branching of the sporangiophore. This group com- 

 prises Miiiur tipiii<ii>u.<y M. riri'iinllniih's, M. (i/fcrintns, as well jis 

 the M. JhnLtii, M.Jtiriniii-us, itc, descril)ed in <; 240. Tin* former 

 will nt)W be described from a morpholoiricil st-;indpoint, their 

 physiological characteristics being deferred for consideration 

 until ^ 239. 



.\fiu-or mu4-edti is the ohlest known species, ami was first fullv 

 de.scribed by (). liHKKKi.D (L) in 1S72. The dcvelojiment of its 

 mycelium has alrea<ly l>een diagrammatii-ally illustrated on 

 p. 2. From tlu* mycelimn itself arise stilV sporangiophores, 

 30 to 40 /* thick and (according tt) the conditions of growth) 

 2 to 15 cm. in height The apt'X of eacli supports a single 

 globular sporangium, which is closely coveied with tine needles 

 of calcium oxalate, and usually measures 100 to 200 /» in dia- 

 meter, though, as shown in Fig. 113, it maybe much smaller 

 under unfavourable comlitions The spores, which are in the 

 shajie of an elon;.'ated ellipsoid, and about twice as Ion*; as thev 

 are broail, may dilYer in size in one and the .siiuu* sjM»ningiuni. 

 the usual measurements, however, being 6 to 1 2 /i and 3 to 6 /» 

 respectively. The cell contents are faint yellow in colour, the 

 nuMubrjine colouile.ss and smooth. The /vgosjKires, the gradual 

 development of whidi is represented in Fig. 101. genninjite bv 

 putting t\)rth direct an uidu-ancheil sporangiophore with an 

 attached spomngium. This species does not produce gemnue. 



A s]H>rangivnu of Mucor mucilatjiueus — which was first men- 

 tioned by linKi Ki.i) (TV.) is .shown in Fig. 112. which als<i 

 reveals the consideralde dimensions of the spores. Thesi» are 



