186 ON THE SAPROLEGNIE^. 



The Rev. M. J. Berkeley, in his "Introduction to Cryptogamic 

 Botany," places the Saprolegniese amongst the Algae, but speaks of 

 them in the following words : — " The globular sporangia . . . 

 with their spores resemble so closely those of some of the Muco- 

 rine Fungi, that I should not hesitate, were there any other 

 instance of the production of zoospores with flageUiform append- 

 ages amongst Fungi, about their removal from Algse." And in 

 another place, when describing the Mucorine Fungi, he says : — 

 " The aquatic moulds which have been described under Algae m\\ 

 in all probability find their resting-place here, and, if so, will 

 present the singular anomaly of true zoospores amongst Fungi." 

 Recent investigation has fully confirmed the accuracy of this con- 

 jecture, and has also demonstrated that Saprolegnieae is by no 

 means the only group of Fungi amongst which true zoospores are 

 to be found. 



We have now to consider the development and structure of 

 this fungus so far as it is at present known, for it still presents a 

 wide field for enquiry. The first point to be noticed is the pro- 

 bable relationship that exists between the Saprolegniece and the 

 parasite called Empiisa Muscce^ a member of the order Torulacei, 

 which proves fatal to house-flies in the autumn. The mycelium 

 bores through the cuticle of the living fly, and immediately breaks 

 up into short joints, which diffuse themselves through the body of 

 the fly, and everywhere multiply by division, until they have 

 appropriated all the nutritious matters which are available to them, 

 and the fly becomes covered with a powdery substance, which 

 consists of extruded conidia. These conidia are capable of form- 

 ing secondary conidia, which would infect other flies, and, in turn, 

 give rise to fresh conidia in the bodies of their hosts. But should 

 such a diseased fly fall into water and remain there, it soon 

 developes a filmy mouldiness around it, which rapidly increases 

 till the fly appears to be enclosed in a white fluffy ball, and on 

 microscopic examination this ball is found to consist of a fungus 

 indistinguishable from Saprolegnia. 



No researches have as yet been made on this subject, but the 

 following points are worthy of consideration : — The process of 

 reproduction in Fungi may be either asexual or sexual. It is said 

 to be asexual^ when a part of the plant which becomes detached 



