SPECIES OF CHOANEPHOItA. 



109 





beco 



nes so great that chlamydospores alone are produced. If, then, we take general 

 national activity rather than the production of sexual fructification as the true 

 criterion, the Choanephora described in the present case ought to be regarded as a 

 parasite endowed with -facultative" saprophytism, whilst if Dr. Bary's standard be 

 retained it must be regarded as a saprophyte endowed with -facultative" parasitism. 



The phenomena appear to indicate that we have to deal with a 



itionary stag 



£i. 



between the pure saprophytism of the other species of Choanephora and pure parasitism, 

 but one in which adaptation to parasitic existence has advanced so far that nutritional 

 facilities are present in greater degree in the latter than when the plant occurs as a 

 saprophyte. 



In this adaptation to parasitism on phanerogams the plant shows closer affinities tn 

 certain of the Oomycetes, such as Peronospora, than it does to any Zygomycete fur. 

 In the one species of Choanephora we have to deal with a purely saprophytic organi n 

 retaining characters of more primitive type than those which are present where any 

 special adaptation to parasitic existence has arisen, whilst in the other parasitism 

 makes its appearance, not yet of such highly specialised type as to imply adaptation to 

 one particular host, but yet so far evolved that growth attains its maximum in association 

 with it. In this respect the genus presents very generalised characters and forms i 

 connecting link between the parasitic and saprophytic Phycomycetes. But it does 

 more than this, as it presents a curiously large series of affinities to distinct groups, both 

 of the higher and lower fungi generally. In Choanephora Cunning hamiana the normal type 

 of fructification is certainly conidial, for conidial fructification occurs alone under 

 conditions of high nutrition, and is the form which is directly derived from the 

 chlamydospores, whilst sporangic fructification only occurs in association with very defec- 

 tive nutrition and is of a more or less abortive type. But in the other species conidial 

 fructification only occurs under conditions of excessive nutrition, and then does not attain 

 such a high degree of evolution as it does in its ally, whilst the sporangic fructification 

 is developed under most circumstances, attains a high degree of evolution, and is that 

 which originates direct from the chlamydospores. The former species has thus a special 

 relation to the conidiiferous series of higher fungi which culminates in the Basidiomycetes, 

 and the latter to the sporangiferous series culminating in the Ascomycetes. Special affini- 

 ties to various groups of Phycomycetes are also indicated by the phanerogamic parasitism, 

 the occasional Peronosporoid fructification, and the Rhizidiseoid character of the sporangia I 

 spores of the species here specially dealt with, and by the markedly oomycete character- 

 which the sexual fructification of both species in. many cases manifests. The genus in 

 fact in a sense appears to form a sort of centre from which various groups of both the 

 higher and lower fungi radiate, and seems, therefore, to be worthy of very special 

 attention. In so far as its sexual fructification is concerned it is less specialised than 

 the Oomycetes, and in respect to its conidiiferous and sporangial fructifications le*s 

 specialised than the two great groups of higher fungi have become, and it, therefore, 



to have 



retained ancestral characters in remarkably high degree 



Choanephora Simsoni, Cunningham, n.sp. Conidia and spores fusiform, with a brow 

 itudinally striate epispore; spores provided with radiant terminal processes. 

 Parasitic on Ipomcea rubro-ccerulea , Hook., and Zinnia elegans; saprophytic in variot 



infusions, &c 



Calcutta 



