RESEARCHES ON THE MUCORINI. 71 



caducous sporangioles destitute of a columella. All the 

 branches except those which bear the sporangioles terminate 

 in a point and the branches of each successive order, which 

 are shorter than those of the preceding, are placed in a kind 

 of false verticil on a more or less swollen dilatation (fig. 21). 

 Whatever the size of the sporangium the spores are always 

 nearly uniform. They are colourless or slightly bluish, oval, 

 and "008 mm. in length, by -005 in breadth. 



Ch^tocladium. 



The type of this genus was first described by Berkeley and 

 Broome as Botrytis Jotiesii} This was erected into a genus 

 by Fresenius, who called it Chcetocladium Jonesii? Quite 

 recently it has been studied by De Bary and Woronin.^ At 

 first, we ourselves accepted the conclusion arrived at by these 

 latter writers, that ChcBtocladium belonged to the cycle of 

 Mucor MucedoJ' 



Chcetocladium Jotiesii. — By sowing, unmixed with other 

 spores, in a drop of orange juice or decoction, in a cell, a 

 small number of the reproductive bodies of this species, or 

 better still, a single one, and by watching from hour to hour 

 its development, it is easily proved that the reproductive 

 bodies of Chatocladium Jonesii, regarded hitherto as simple 

 acrogenous spores, such as those of Botrytis, are really small 

 caducous sporangia, containing only a single spore, like those 

 of Helicostylam, Thamnidium, Chcetostylum, in fact, that 

 ChcBtocladium Jonesii is perfectly independent of Mucor 

 Mucedo, or of any of the Mucorini, either as a reproductive 

 system or as a parasite. 



These reproductive bodies (fig. 22), when detached from 

 the plant at their maturity, are a more or less slaty blue. 

 Their external surface bristles with calcareous granules, 

 more or less developed, which have not escaped the observa- 

 tion of Berkeley and Broome, and a small portion of the 

 broken pedicel is sometimes still attached (fig. 23, a). It is 

 not rare to find an external membrane distinguishable from an 

 internal spherical body, since the spore does not in this 

 case completely fill the cavity of the sporange ; but it is 

 frequently diflScult to observe this, from the spore being 

 everywhere in intimate contact with the inner wall of the 

 sporangium ; this is also the case with the monosporic spo • 



I ( 



Ann. and Mag. Nat. Hist.,' 2ad ser., 1854, xiii, pi. 15. 



2 ' Beitr. z. Mykol.,' 1863, p. 97. 



3 ' Beitr. z. Morph. u. Phys. der Pilze,' 2nd ser., 1866, pi. 18. 



4 'Comptes Rendus,' Ap. 8, 1872. 



