234 THE NORTH AMERICAN SLIME-MOULDS 



flattened tubules extended inwardly among the spores, everywhere 

 marked by transverse wrinkles, ridges, and warts, the free ends of the 

 ultimate branchlets rounded, concolorous with the spores; spore- 

 mass, when fresh, rosy, or ashen with a rosaceous or purplish tinge, 

 becoming with age sordid or ochraceous, spores by transmitted light 

 colorless, minutely roughened or reticulate, 5-6 p.. 



This is not only a cosmopolitan species, but is no doubt the most 

 common slime-mould in the world. Found everywhere on decaying 

 wood of all sorts, more particularly on that of deciduous trees. It 

 has likewise been long the subject of observation. It is doubtless the 

 "Fungus coccineus" of Ray, 1690, and the type of Micheli's genus as 

 here, 1729. The diflferent colors assumed, from the rich scarlet of 

 the emerging Plasmodium to the glistening bronze of the newly 

 formed aethalium, have suggested various descriptive names, — as L. 

 miniata Pers,, L. chalyheum of Batsch, and L. plumbea Schum, The 

 peridium is by authors described as double. This is for description 

 only. In structure the outer and inner peridium completely blend. 

 The outer is predominately vesiculose, the inner more gelatinous. 

 For discussion of the microscopic structure see under the next species. 



Common. New England, west to Nebraska, South Dakota, Col- 

 orado, Washington, Oregon, California; Alberta to Nicaragua. 



Lycogala terrestre Fr,, Syst. Myc, III., 83, appears to be a variety 

 of the present species. In spores and capillitial thread the forms are 

 indistinguishable ; the difference is a matter of size, and to some 

 extent, of the color of the wall. The specimens are a little larger, 

 depressed and angular. The peridium is paler, smoother, though 

 sometimes almost black, thin, ruptured irregularly. But the form 

 and color of the peridium in the sporocarps of the older species vary 

 much in response to external conditions ; on a substratum allfording 

 scant nutrition the forms of fructification are minute; and in all 

 cases, if maturity be hastened, the peridium responds in darker colors. 

 Under more favorable conditions the wall is smoother and brighter. 



2. Lycogala flavo-fuscum (Ehr.) Rost. 



1818, Diphtherium flavo-fuscum Ehr., Syl. Myc. Berol, p. 27. 

 1829, Reticularia flavo-fusca (Ehr,) Fries, Syst. Myc, III,, p, 88, 

 1873. Lycogala flavo-fuscum (Ehr.) Rost., Versuch, p. 3. 



