11. INTRODUCTION. 



the monograph only a passing notice is given of the first divi- 

 sion, and in the more recent " supplement ' ;| it is not mentioned 

 at all. The inference to be deduced from this is that the 

 Exosporous Mycetozoa are regarded as an encumbrance to the 

 system, and are intended to be ignored. 



The Mycetozoa proper being thus reduced to unity, our illustra- 

 tions will be understood to refer to these alone. As in the 

 Agaricini, so in the Myxomycetes the first steps in classification, 

 relate to the colour of the spores. Two sections include the 

 species (1) with violet spores, and (2) those having spores 

 otherwise coloured. The Amaurosporce and the Lamprosporw 

 are the two primary sections, each of which is subsequently 

 again divided into two subsections, in one of which no evident 

 capillitiuni is present, and in the other some kind of capillitium is 

 always developed. 



A careful comparison of the analytical key, and the fuller 

 description of the orders, families and genera, which are all re- 

 produced in the following pages, will enable the student readily 

 to master the distinctive features of the details of the system. 



As the old method was based wholly on external features, so 

 the new has nearly all its essential characteristics relating to 

 internal structure. If there is any one feature in which the 

 Rostafinsld method is more assailable than another it is the too 

 slight regard which is given to external features. Naturally 

 enough, in escaping from one extreme, the rebound has been to 

 the other. Time and experience will undoubtedly hereafter 

 develop a " happy medium." 



In making use of this system the first determination requisite 

 is the colour of the spores, then the presence or absence of a 

 capillitium, and finally the character of the capillitium, when 

 present, in all its details. Undoubtedly the leading idea of the 



