46 
E. W. OLIVE AND H. H. WHETZEL 
showed that the spores produce at once promyceHa and that this form 
is therefore a short-cycled Endophyllum and not a heteroecious form, 
as had been thought. 
In all, we germinated 13 aecidioid and uredinoid forms, in some 
cases repeating the experiment several times in order to confirm our 
earlier observations. In 7 of these, the spores germinated very 
sparsely and very slowly; resulting at the end of 24-48 hours in a 
few long, unseptated germ-tubes. We therefore became convinced 
that in these 7 species (Aecidium passifloriicola P. Henn., A. tuhulosum 
Pat. & GailL, A. Tournefortiae P. Henn., A. abscedens Arth., A. 
Borreriae Pat., Uredo Trichiliae Arth. (ined.), and the aecial stage of 
Uromyces proeminens (DC.) Pass.) we were dealing in all probability 
with true aecia and therefore with long-cycled forms. We secured, 
in fact, considerable evidence in two of the above cases as to possible 
alternate hosts; coming to the conclusion that the first species was 
probably associated with Puccinia Scleriae (Paz.) Arthur and the 
second with Puccinia suhstriata Ellis & Barth. Mr. Stevenson, of the 
Experiment Station at Rio Piedras, had also come to a similar con- 
clusion in the case of the second — A. tuhulosum on Solanum. 
The slow and meager germination of the true aeciospores of the 
above 7 forms is in marked contrast to that of the spores of the short- 
cycled rusts described below. In the latter case, in an incredibly 
short time, 10 or 12 hours or even less, nearly all of the spores germin- 
ated. When these spores are floated on the surface of water drops in 
moist chambers, they push out into the free air a profuse mass of 
unbranched, septate promycelia (basidia), each bearing the 4 (or in 
some cases only 2) basidiospores (sporidia). It must be kept in mind, 
however, in germinating these forms, that a source of error is liable to 
arise if one is not extremely careful in the floating of the spores. When 
entirely immersed, they always grow out into long tubes, rarely forming 
sporidia, and might thus easily be mistaken for ordinary aeciospores. 
The germ-tubes vary considerably in length as well as in other 
characteristics in these Endophyllum-like forms. Sometimes, indeed, 
even in the same lot of germinations, there is considerable variation, 
due perhaps to their being grown sometimes in moist air only, 
sometimes partially in water. Two of the species showed, how- 
ever, a most remarkable variation, which is, in contrast to the above, 
apparently not at all environmental. The spores of Endophyllum 
Stachytarphetae and of E. circumscriptum, on germinating, produce 
