2 
Journal of Agricultural Research voi. xxvi, no. i 2 
whole cell collapses. The haustorium remains small, dense, and rounded, 
and soon dies. When haustoria form in an epidermal cell they may 
expand and function for a time, but ultimately succumb. 
Each attempt of the fungus to make a haustorium wastes some of its 
substance. Its diminishing amount of living matter is continually 
transferred to the growing tips, leaving the older hyphae empty. 
Older enfeebled fungi elicit less violent reactions in the host cells, but 
here, too, some of the cytoplasm moves to the haustorium and surrounds 
it, and the nucleus is to be found near by. Here, too, the haustorium 
and the host protoplasm near it die, but the host cell does not collapse. 
Host tissues in Mindum for some distance around the fungus are 
plasmolyzed and an occasional cell wall is greatly swollen. 
Near the fungus, nuclei die and plastids become smaller and disappear. 
Farther out, the nuclei live and even expand slightly, and the plastids 
persist. 
Form III evidently secretes substances into the host cells. Baart 
and Kanred tissues are stimulated and produce additional food that 
meets the needs of the fungus. Mindum tissues, on the contrary, are 
killed outright by the more concentrated solution of this substance. 
The outer regions of the infection in Mindum are slightly stimulated, 
but it is not clear whether this is due to a dilute solution of the same 
toxin that killed the central cells or to secondary substances which have 
formed in the dying cells and diffused out from them. 
LITERATURE CITED 
(i) Aamodt, Olaf S. 
1922. THE INHERITANCE of RESISTANCE TO SEVERAL, BIOLOGIC FORMS OF 
PUCCINIA GRAMINIS TRITICI IN A CROSS BETWEEN KANRED AND MAR¬ 
QUIS wheats. (Abstract.) In Phytopathology, v. 12, p. 32. 
<2) Allen, Ruth F. 
1923. A CYTOLOGICAL STUDY OF INFECTION OF BAART AND KANRED WHEATS BY 
puccinia graminis TriTici. In Jour. Agr. Research, v. 23, p. 131- 
152, 6 pi. Literature cited, p. 149-151. 
(3) Armstrong, S. F. 
1922. THE MENDELIAN INHERITANCE OF SUSCEPTIBILITY AND RESISTANCE TO 
YELLOW RUST (PUCCINIA GLUMARUM, ERIKSS. ET HENN.) IN WHEAT. 
In Jour. Agr. Sci., v. 12, p. 57-96. List of papers referred to in the 
text, p. 96. 
4) Bary, Anton de. 
1866. NEUE UNTERSUCHUNGEN tJBER DIE UREDINEEN INSBESONDERE DIE 
ENTWICKLUNG DER PUCCINIA GRAMINIS UND DEN ZUSAMMENHANG 
derselben mit aecidium BERBERiDis. In Monatsber. K. Preuss. 
Akad. Wiss. Berlin, 1865, p. 15-50, 1 pi. Bibliographical footnotes. 
<5). .. 
1887. COMPARATIVE MORPHOLOGY AND BIOLOGY OF THE FUNGI MYCETOZOA AND 
bacteria, xviii, 525 p., 198 fig. Oxford. Bibiographical footnotes . 
(6) Biffen, R. H. 
1907-12. studies in the inheritance of disease resistance, i-ii. In 
Jour. Agr. Sci., v. 2, p. 109-128; 4, p. 421-429. 
(7) Blackman, V. H., and Welsford, B. J. 
1916. STUDIES IN THE PHYSIOLOGY OF PARASITISM. II. INFECTION BY BOTRYTIS 
cinerEa. In Ann. Bot., v. 30, p. 389-398, 2 fig., pi. 10. Literature 
cited, p. 397. 
(8) Boyle, C. 
1921. STUDIES IN THE PHYSIOLOGY OF PARASITISM. VI. INFECTION BY SCLEROTINIA 
libertiana. In Ann. Bot., v. 35, p. 337-347 > pi- I 4 - Literature 
cited, p. 346. 
*(9) Brown, W. 
1915. STUDIES IN THE PHYSIOLOGY OF PARASTISM. 1. THE ACTION OF BOTRYTIS 
CINEREA. In Ann. Bot., v. 29, p. 313-348. References, p. 348. 
