352 
AMERICAN JOURNAL OF BOTANY 
[Vol. 9, 
9. Engelke, C. Neue Beobachtungen iiber die Vegetationsformen des Mutterkornpilzes 
Claviceps purpurea TulsLsne. Hedwigia 41 : 221, 222. 1902. 
10. Ewins, A. J. Acetylcholine, a new active principle of ergot. Biochem. Journ. 8: 44-49. 
1914. 
11. Kuehn, J. Uber die Entstehung des M utter korns. Ber. Sitz. Naturforsch. Ges. Halle 
12-14. 1863. 
12. Meyer, B. Untersuchungen iiber die Entwickelung einiger parasitischer Pilze bei 
saprophytischer Ernahrung. Landw. Jahrb. 17: 915-945. Pis. 16-19. 1888. 
13. Pittenger, P. S. Biochemic drug assay methods. Pp. 158, 88 fig. 1914. 
14. Stager, R. Infectionsversuche mit iiberwinterten Claviceps-conidien. Mycol. Cen- 
tralbl. i: 198-201. 1912. 
EXPLANATION OF PLATES 
Plate XVI 
Growths of Claviceps purpurea 
Fig. I. On rye-screening agar, early stage. 
Fig. 2. On rye-screening agar, late stage. 
Fig. 3. On rye-seed agar, late stage. Photographed when agar had begun to shrink 
from sides of flasks. Appearance of growths unaffected. 
Plate XVII 
Fig. i. Germinating spores. A-C, X 900; D, X 385. 
Fig. 2. Spores, rye-screening agar, vermiculate area. X 900. 
Fig. 3. Spores, rye-seed agar, vermiculate area, later stage. X 900. 
Fig. 4. Mycelium, Petri dish culture, rye-seed agar. Full size. 
Fig. 5. Mycelium and spores, rye-screening agar. X 900. 
Fig. 6. Mycelium on carrot. X 385. 
Fig. 7. Mycelium on rye-screening agar. X 900. 
Fig. 8. Mycelium on carrot. X 385. 
Fig. 9. Mycelium on rye-screening agar. X 900. 
Plate XVIII 
Growths on mashes after three months 
Fig. 
I. 
On white corn meal. 
Fig. 
2. 
On yellow corn meal. 
Fig. 
3- 
On rye seed. 
Fig. 
4- 
On rye screenings. 
Fig. 
5. 
On rye heads after flowerin 
Fig. 
6. 
On potato. 
Fig. 
7- 
On carrot. 
Fig. 
8. 
On string bean. 
Fig. 
9- 
On sweet potato. 
Plate XIX 
Fig. I. Six months' growth on white corn meal. 
Fig. 2. Longitudinal section through same. 
Fig. 3. Section through surface portion of growth in the same flask, showing tend' 
ency to epidermal formation. X 200 (approximate). 
Figs. 4, 5. Sections through center of growth, showing pseudo-parenchyma, 
(approximate). 
Fig. 6. Section of ergot sclerotium. X 200 (approximate). 
X 200 
