Introduction 5 



usual places, but more successfully in places well suited for their 

 development and with much habitat material. Such localities 

 are secluded forest-areas with large trees of different kinds. 

 There should be many fallen trees and logs in various stages of 

 decay, with undergrowth and bushes to provide shade. The 

 situation should be moist, either by the natural topography of the 

 land and drainage, or by the presence of brooks, lakes, or springs. 

 Localities suitable for mushrooms and other fungi are also fit for 

 the Mycetozoa. It is surprising how many species may be found 

 in a small area if repeatedly visited and intensively searched, and 

 it is not unusual to collect fifty or more species in a single day. 



Specimens of the fruiting bodies collected in the field, should 

 be transported in old cigar-boxes in the bottom of which a layer 

 of corrugated cardboard has been placed. They should be pinned 

 therein with pins having large, glass heads. On arrival home, the 

 specimens should be removed, trimmed somewhat of the unneces- 

 sary wet material, and placed in porous, cardboard boxes so that 

 they will dry thoroughly. Precautions should be taken against 

 insects and the growth of molds. When dry, they should be 

 trimmed to the size desired and glued into small cardboard boxes, 

 where, with the addition of a pinch of ordinary naphthaline flakes, 

 they will keep indefinitely. 



The classification of the Mycetozoa is based upon the charac- 

 ters of the fruiting bodies, and (following Lister) the group is 

 regarded as a class and divided into two subclasses, the Exosporeae 

 and the Endosporeae. The first has but a single species, Ceratio- 

 myxa fruticulosa, which develops sporophores with spores on the 

 outside. All other species are in the Endosporeae and develop 

 sporangia or similar bodies with spores on the inside. The Endo- 

 sporeae are divided into the orders Amaurochaetales with spores 

 violet-brown or purplish gray in color, and the Cribrariales 

 with spores variously colored but not violet-brown or purplish 

 gray. The Amaurochaetales have two suborders, the Physariineae 

 in which the sporangia are provided with lime, and the Amauro- 

 chaetineae which have no lime. The Cribrariales have two sub- 

 orders, the Dictydiineae which have no capillitium, and the 

 Calonematineae in which a capillitium is present. The further 

 division into families, genera, and species, as they are known to 

 occur in North America, is followed later in the text. Several 

 other genera, and about forty more species, are known from other 

 parts of the world, but so far have not been reported from North 



