RESEARCHES ON THE MUCORINI. 75 



of which gradually diverge and are studded with hooked 

 branchlets, gives a habit altogether different from that of Ch. 

 Joncsii, and supplies, perhaps, the best proof of the specific 

 difference of the two plants. 



This diffuse mycelium, the offspring of a single spore, 

 spreads itself in four days, little by little, through the whole 

 drop, passes its borders, and extends over the covering-glass 

 and covers a circular space 5-6 mm. in diameter. On the 

 fourth day a few of the principal hyphee exhibit a few trans- 

 verse septa. The fifth day, the extremities of the hyphae 

 which occupy the periphery of the drop put out slender 

 branches into the air of the cell. Occasionally, these aerial 

 prolongations may be the ends of the hyphae themselves, but 

 more usually they are a development of one of the branches 

 of a lateral process (figs. 30, 31). In this case the other 

 branches of the process grow^ and, becoming felted together, 

 form a more or less complicated mass investing its base. On 

 the sixth day a large number of these aerial filaments bear 

 on lateral branches groups of bluish monosporic sporangia 

 (figs. 30, 32). 



Cultures of this kind often repeated prove that Chceto- 

 cladium Brefeldii may be perfectly autonomous, and Brefeld's 

 failure attributable to many causes, possibly amongst others 

 to an unfavorable medium, is not conclusive. 



When the spores of Ch. Brefeldii are mixed with those of 

 Mucor Mucedo, wherever the apex of a branch of one of the 

 lateral processes of a hypha of the former comes in contact 

 with any part of a hypha of the latter, it forms an intimate 

 attachment, and finally, by the absorption of the intervening 

 walls a complete continuity between the branch and the hypha 

 (figs. 33, 34). The other branches of the process immediately 

 develope and form about the point of union a felted mass, 

 more or less complicated. Some of them in different stages of 

 development will be found from the second day after the 

 sowing and indicate points of union between the two 

 systems of mycelium. 



Union of hyphae may take place when only those of 

 ChcBtocladium are concerned. Fig. 35 represents three spores 

 s, s' , s' , of Ch. Brefeldii, which have generated side by 

 side, and the hyphae of which have fused, so that it is 

 impossible to determine their points of union. Fig. SQ shows 

 that two branches of a hypha have curved towards each 

 other, forming a loop. This property of anastomosis of 

 the mycelium which is possessed in so high a degree by 

 Ascomycetes, Penicilliutn, Botrytis, Arthrohotrys, here 

 appears for the first time amongst the Mucorini, al- 



