258 Journal of Agricultural Research voi. xix, no. 6 



not new that certain fungous parasites may exist in the vegetative state 

 in the seeds of their hosts and be thus transmitted from one generation 

 to another. Even before this was established for certain of the cereal 

 smuts, various workers had endeavored to show this condition for the 

 cereal rusts. The discovery that certain smuts were systemic in their 

 infection gave impetus to further research along this line. 



The purpose of the investigations reported here was to determine 

 whether or not Puccinia graminis triiici Erkiss. and Henn. can be trans- 

 mitted to the seedling by being carried over with the seed grain. 



OCCURRENCE OF RUST IN SEEDS AND SEED PARTS OF VARIOUS 



PLANTS 



The earliest report that the v/riter has been able to find that stemrust 

 may attack the seed and seed parts of grain was made by W. G. Smith 

 in 1885 (2j). He found telia of Puccinia graminis in the pericarp of oat 

 kernels and figured teliospores within the oat grains lying inside the 

 aleurone layer and between that and the endosperm. His drawings and 

 notes, however, leave much to be desired. In 1886 {24) the same 

 author figured aecia embedded in the fruits of the barberry. Maddox 

 {18, p. 20) noted rust infection upon — 

 the young haU-grown grain . . . before it had started to go out of the milk stage. 



He does not state to which rust he refers. Pritchard {22, p. 151) in 191 1 

 figured stemrust upon wheat kernels and stated that telia and fragments 

 of mycelium were found in abundance in the pericarp of wheat kernels 

 and that seed infection occurs very frequently even in rust-free years. 

 Other reports have been made of P. graminis upon the caryopses of 

 wheat, oats, barley, and various grasses, and the writer has observed 

 this condition upon all of the above-mentioned hosts. 



Puccinia glumarum (Schm.) Erikss. and Henn. is also known to occur 

 commonly upon the caryopses of wild and cultivated Gramineae. Beau- 

 verie (i, 2) has recently reported at length upon this phenomenon and 

 states that if the seed is hulled the sori are produced upon the interior 

 of the glumule, while if the seed is naked they are formed in the pericarp. 

 He found this rust more or less abundant in the caryopses of Triticum 

 vulgare, Hordeum vulgare, Brachypodium pinnatum, Agropyron caninum, 

 and Bromus mollis. He also reports finding P. simplex on barley kernels 

 and P. coronata agropyri ^ on Agropyron re pens. Blaringhem (j, p. 86) 

 found somewhat the same conditions reported by Beauverie. Eriksson 

 and Henning (jo, p. igg, pi. 7, 9)) fully describe and give excellent figures 

 of whole kernels and cross sections of kernels infected with P. glumarum.^ 

 Various other rusts have been reported as occurring upon seeds and seed 

 parts of various plants. Carleton (6, p. 28-2g) has reported the occur- 



1 It is not clear what rust is referred to by this name. 



» These authors cite several former observations of P. glumarum upon kernels of wheat, the earliest of 

 which was by Schmidt {lo, p. 454) ia 1819. 



