APPf^NDICES V, VI 695 



Family 9. Reticulariace^. — Sporangia closely compacted and usually forming 

 an aethalium, true capillitium none. 

 Sporangia columnar, inner walls reduced to straight slender threads. 



Diclyde^halium. 

 Sporangia interwoven, inner wall reduced to broad bands. Enlcridium. 

 Sporangia interwoven, inner walls laciniated. Relicularia. 

 (b) Capillitium present; a system of uniform threads. 

 Family 10. Trichiace^. — Sporangia single, rarely in an aethalium. Peridium 

 without thickenings, without lime. Capillitium of tubular simple, or 

 branched, free threads. Spore mass as capillitium, yellow or red, 

 rarely white or brown, never violet. 

 *Capillitium of free elaters, or an elastic network of spiral thickenings. 

 Elaters free, spirals distinct. Trichia. 

 Elaters free, scanty, spirals obscure. Oligonema. 



Elaters combined into a web or network. (Hemiirichia ( = Hcmiarcyria). 

 **Capillitium a profuse network of threads (usually scanty and free in Peri- 

 chcena populina), thickened with cogs, half rings, spines or warts. 

 Sporangia stalked, sporangial wall evanescent above. Arcyria. 

 Sporangia sessile, clustered, the walls single, persistent. Lachnobolus. 

 Sporangia sessile, the walls usually double. Perichcsna. 

 ***Capillitium coiled and hairlike, or straight, and attached to the sporangial 

 wall. 

 Capillitium straight. Dianema. 

 Capillitium penicillate, spirally banded. Prololrichia. 

 ****Sporangia forming an aethalium; capillitium consisting of branched color- 

 less tubes. 

 Capillitial tubes, thick-walled where they traverse the cortex, thin-walled 

 among the spores. Lycogala. 



APPENDIX VI 



KEY FOR THE DETERMINATION OS SPECIES OF MUCOR 



Laboratory Work. — The teacher will find it good educational practice to supply 

 the class with material of the commoner moulds in order that they may become 

 familiar with the general morphology of the ZYGOMYCETALES. 



From the standpoint of taxonomy the columella is an organ of the first im- 

 portance. The position of the columella in relation to the wall of the sporangium 

 has been described as "free," "subjacent," "infundibuliform." 



Terms which have been applied in systematic works to the different shapes of 

 the columella' are illustrated in Fig. 240, a to /, inclusive. 



The spores, whether sporangiospores, conidiospores, chlamydospores, oidiospores 

 or stylospores (as in MortiereUa), have been described by special names, as spheric, 

 ellipsoidal, oval, dumbbell-shaped, spindle-shaped, bottle-shaped, bead-shaped, etc. 



•Lender, Dr. Alf.: Les Mucorinees de la Suisse, 1908: 29. 



