20 INTRODUCTION 



Systematic Arrangement. — In preparing this Catalogue of the 

 collection of Mycetozoa in the British Museum, the arrange- 

 ment of orders and genera given by Rostafinski in his 

 Monograph* has in the main been followed, with such altera- 

 tions as observations made during recent years have rendered 

 necessary. De Bary made the group the subject of minute 

 and thorough investigation ; f and Rostafinski, while studying 

 under him at Strassburg, devised a system of classification 

 which is clear and comprehensive, and is now generally 

 accepted. 



The division by Rostafinski of the main section Endosporeae 

 into two parts, distinguished by the colour of the spores, has 

 been objected to as being artificial and wanting in universal 

 application, but the cases which offer difficulty with regard to 

 their position under this scheme are few, and on the whole 

 the species range themselves under the separate heads in a 

 remarkably natural manner. 



Although the search for specimens of the Mycetozoa has 

 been comparatively limited, owing, no doubt, to the small size 

 of the objects, yet in consequence of the persistent nature of 

 the sporangia, we possess, in the different herbaria, specimens 

 representing the gatherings from many countries during more 

 than half a century, and some of them dating back a 

 hundred years. Where they have escaped rough treatment, 

 they completely retain their specific characters. When we 

 consider the cosmopolitan distribution of the species, owing, 

 we may conclude, to the long-continued vitality and minuteness 

 of the spores, it may be doubted whether any hitherto 

 unsearched region will add very largely to the number with 

 which we are already acquainted. It is their life history 

 which is at present imperfectly known, and it is in this 

 direction that the important work of the future must lie. 



* Sluzowce (Mycetozoa) Monographia (Paris : 1875). 

 t Comp. Morph. and Biol. Fungi, Mycetozoa, etc., 421. 



