224 THAXTER. — MONOGRAPH OF THE LABOULBENIACE^. 
this determinate character is absolute, as a rule, in the more highly specialized portions of the thallus, like 
the perithecia and compound antheridia. In considering the variations of the receptacle, it is thus con- 
venient to distinguish in a general way, those forms which are determinate, as in Stigmatomyces, Cera- 
tomyres etc., from those in which, as a result of secondary cell divisions, whether terminal or intercalary, 
the cell-number becomes more or less variable, as in Ectei?wmyces, Dichomyres etc. In the second of these 
types, two categories may be further distinguished; namely those in which the indeterminate character 
results from an intercalary division of the main axis, a condition well illustrated by Dirneromyces pin- 
imtii.s; Plate XXIX, fig. 1G, and secondly those in which the secondary production of cells is due to the 
development of branches, or secondary axes, such as occur in Kainomyccs, Monoicomyecs, Dimorpltomyces, 
Dichomyces and other genera, usurping the function of the primary receptacle by giving rise to perithecia, 
or antheridia, or both. 
It is thus convenient to distinguish types which possess a primary receptacle, only, corresponding to 
the original axis of the basal spore-segment, and immediately concerned in the production of procarpic 
branches; from those in which the primary receptacle, though present, is sterile; the production of 
sexual organs being relegated to secondary axes which branch laterally from it and may be distinguished 
ms weondary receptacles. Among genera of the first category, in which the primary receptacle is determi- 
nate and fertile, those types in which the latter consist of two superposed cells are the most common, and 
of these the simplest condition is illustrated by Amorphomijces . In neither sex of this dioecious genus is 
it associated with sterile cells or appendages; the type being quite anomalous in possessing a continuous 
spare, from which the procarp in the female, as well as the antheridium in the male, develop terminally. 
In no other genus is the axis of the procarp continuous with that of the primary receptacle, although, as 
in Kainomyces, it may sometimes bear this relation to its branches. This condition is directly depend- 
ent on the fact that in all other genera, even in the very closely related Dioiromyce.s, the spore is once- 
septate, the distal segment becoming a "primary appendage," which is cither sterile, or is concerned in 
the production of antheridia. This condition is illustrated on the one hand by Dwicomyees, the species 
of which possess a two-celled receptacle surmounted by a sterile portion corresponding to the distal 
spore-segment and bearing the procarp laterally; and on the other bv such genera as K ucant haromy ces, 
Shrjmatomyce,, Corethromyces and many others, in which the terminal spore-segment produces an antheri- 
dia] appendage of varying complexity. 
Instances in which the primary receptacle is two-celled and sterile, are found in both the monoecious 
and dioxious genera, and by far the most remarkable illustration of this condition is seen in Ilcrpomyces, 
m M huh the perithecia are borne on secondary receptacles that are more clearly differentiated than in any 
other instance. n the female individuals of the species of this genus, Plates XXXIX-XLI, a variable 
number of branches .nay thus arise, which originating as simple cylindrical filaments, soon become cellu- 
lar forming secondary receptacles which creep more or less extensively, or are variably multiplied in 
--t spoctes by ranching; perforating the host- integument, as has been ab„ve described, by means 
1ml- ! ^ rend ° r thCSe StmCtUreS lnde P endent of ** °*^ f-t as far as their food- 
Z n T " PeCUHar C ° nditi0n ^ " *"»* COnfi - 1 to the female individuals, although 
be, /descn k 1 i " ^^^ * «* ^ Branches which become adherent to the host have 
*,i , i m „„d n0 : t!, rV nStanCe ' »»+ t** « ^own to the writer in one other peculiar dioecious 
genus as ut undeserved, but it „ not difficult to imagine that such a condition might ither have origi- 
