424 SUMMARY OF CURRENT RESEARCHES RELATING TO 



resting-spore of the Synchytrium, inclosed in and entirely filling up 

 the nutrient cell. It is of a shortly elliptical or spheroidal shape, 

 from 0*14-0 "126 mm, in its largest diameter, and inclosed in a 

 double wall. These develope and form swarm-spores in the spring in 

 the same way as other species of Synchytrium ; but further details are 

 wanted. The trichomes of the eecidium are unicellular and thin- 

 walled, and when old coil hygroscopically. 



Pathog^enous Mucorini, and the Mycosis of Rabbits produced 

 by them.* — L. Lichtheim has found two species of Mucorini which 

 cause pathogenous phenomena when introduced into the blood of 

 rabbits. One of these made its appearance normally in white bread 

 when placed in the breeding oven, in the form of a dense white silky 

 flock, soon entirely covered by Aspergillus. This was propagated 

 separately on strips of nutrient gelatine spread on glass plates. If 

 the temperature of the chamber was not too high, the spores swelled 

 up on the third day and put out a germinating filament on one side ; 

 on the third or fourth day these had grown into a copiously branched 

 unseptated mycelium, which gradually completely overspread the 

 nutrient substance. On the third or fourth day aerial branches 

 appeared, the formation of sporangia commencing very soon at their 

 apex, the other portion turning back after the manner of the stolons 

 of Mucor stolonifer. The sporangiophores are usually simple, rarely 

 dichotomously branched ; opposite to them rhizoids are formed ; the 

 sporangia are black, smooth, and globular. The spores are nearly 

 globular, strongly refractive, and inclosed in a single membrane. 



The second species was less common, and is distinguished from 

 all known Mucorini by its very small size. It appeared in a gelatine- 

 culture of infusion of bread, and was propagated in the same way 

 as the first. The mycelium is loose and crinkled ; the sporangia 

 extremely small and colourless. It spread very slowly over the 

 nutrient substance, forming only distant streaks. From the delicate 

 unseptated mycelium there rise long slender sporangiophores, on 

 which are placed six or eight very small almost transparent sporangia. 

 The sporangia are seated in a small cup-shaped swelling of the 

 sporangiophore, and have somewhat the form of a pear. The spores 

 are nearly globular, and strongly refractive. 



In neither species were zygospores observed. Professor Cohn 

 has named and described them as follows : — 



Mucor rhizopodoformis. — Mycelium at first snow-white; filaments 

 colourless, unseptated ; brownish branches of the mycelium ascend as 

 stolons, then bend, and sink down again on to the substratum ; at the 

 points of contact the mycelium puts out downwards short-branched 

 brownish rhizoids, sporangiophores upwards. Sporangiophores simple, 

 collected into tufts of two or more, unbranched, 120-125^ high. 

 Sporangia globular, seated on the apex of the sporangiophore, black 

 when ripe, with smooth opaque membrane, which is soluble in water, 

 without leaving behind any granular deposit ; diameter 66 ;a. Column 



* Zeitschr. f. Klin. Medicin, vii. (1883) (3 pis.). See Bot. Centralbl,, xvii. 

 (1884) p. 138. y yy f J 



