122 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN 



12-17. Microchaele nana 



12. A young filament, prostrate but beginning to turn ujDward at apex. In this 

 figure and the next the thickness and distinctness of the vagina are somewhat exag- 

 gerated. 



13. An older and normally curved filament, showing two basal heterocysts, a rare 

 or occasional character. 



14. An unusually straight, apparently mature, filament. 



15. Another filament with a curve of a frequent form near base. 



16. Apex of filament shown in Fig. 15. 



17. Base of filament shown in Fig. 15. 



Figures 14 and 15 are enlarged 245 diameters; 12, 13, 16, and 17, 670 diameters. 



Plate 13 



1. Erythrocladia recondita. A photograph of the cndophytc, made after staining with 

 iodine. The larger darker cells are sporocarps. Enlarged 160 diameters. 



2. Erythrocladia vagabunda. A photograph of the endophyte, made after staining 

 with iodine. Some of the larger cells are sporocarps. A small colony of E. recondita, 

 staining more deeply and having smaller cells, is shown near B at the lower right-hand 

 corner, 'where it is more or less intertangled with the E. vagabunda. Enlarged 160 

 diameters. 



Plate 14 



Acrochaetium infestans 



1. Endozoic filaments of the usual form, with two short exserted filaments. In the 

 endozoic parts the outlines of protoplasts only (for the most part) are indicated, the 

 cell walls being almost invisible. 



2. An exserted sporangium sessile on an interior filament. 



3. An exserted filament of three cells, one of which is a sporangium and another of 

 which is probably an immature sporangium. 



4. An exterior filament, with short branches, short hairs, and a single lateral spor- 

 angium. 



5. A single typical cell of an interior filament, showing chromatophore, pyrcnoid, 

 etc. 



6. Exterior filaments, showing sporangia in terminal clusters of three, and also one 

 lateral sporangium. 



7 and II. Short exterior filaments. 



8. A branched exterior filament, showing lateral and terminal sporangia. One of 

 the emptied lateral sporangia is apparently being refilled or regenerated from the sup- 

 porting vegetative cell. 



9. A short exterior filament, showing regeneration of a terminal sporangium. 



10. Part of a plant, showing mode of branching and tortuous course of a part of an 

 interior filament, etc. 



12. An unusually long exterior filament, showing long hairs and short secund branch- 

 lets (solitary or geminate). 



Figure 5 is enlarged 1,040 diameters; the others, 670 diameters. 



Plate 15 

 Acrochaetium affine 



1. A spore attached to margin of the Diclyota thallus. 



2. A spore that has developed a small accessory repent basal cell and is also be- 

 ginning to send up an erect filament. 



