.James R. Weir. 
The Uredospores. 
138 
The Uredospore material was abundant throughout the later 
part of the summer and was found along with the teleutospores 
up to the time of frost. My own observations on the process of 
spore formation in those forms agree in the main with that reported 
by Harper and Holden. The two nuclei at first lie in the long axis 
of the cell but are finally side by side in the transverse axis when 
they both divide simultaneously. The division always results in 
the cutting off in the daughter cells of a pair of nuclei. The two 
nuclei come one from each of the mother nuclei of the mother cell 
so that the nuclei in each cell are not sister nuclei. The next 
division is somewhat different, the upper cell divides unequally, 
a lower cell is cut off obliquely and is much smaller and becomes 
sterile and finally disappears, while the upper cell becomes the 
uredospore. Harper and Holden have suggested that in reality 
this spore is an aecidiospore, but in the light of the research of 
Sapin-Trouffy, Blackman and others, whose work was aimed 
particularly at the nature of the secidium, it seems that they answer 
more nearly to the nature of a typical uredospore with the exception 
that they are borne as conidia and not in the usual manner. This 
exception seems then to be superficial rather than real, as ascidio- 
spores are always produced from uninucleated hyphae while the 
uredospores come always from binucleated hyphae as is the case 
here. 
Haustoria. 
The haustoria as in Coleosporium sonchi-arvensis are normally 
binucleated; whether the haustoria were on the ends of the hyphae 
cells or were formed farther back on the hyphae, I was unable to 
determine. They were usually rounded in form and presented a 
granular appearance. The nuclei were observed to be very near 
each other in some cases in contact. The former condition is 
characteristic for the conjugate nuclei; the latter condition was 
due in all probability to the sectioning. 
LITERATURE. 
1. Arthur, J. C. “Taxonomic Importance of the Spermogonium.” Bull. 
Torrey Bot. Club, XXXI, p. 113, 1904. 
“ The Aicidium as a Device to Restore Vigor to the Fungus.” 
Soc. prom. Agric. Sci., 23rd Ann. Meeting, 1903. 
2 . 
