520 
Journal of Agricultural Research 
Vol. XXXI, No. 6 
The surface of such fruits was smooth and unbroken, and at first 
there was no change in elevation (pi. 1, C). Later, the blackened 
areas tended to become more or less sunken (pi. 1, B). Soon a 
variety of manifestations of this peculiar stem-end rot was observed, 
the one constant feature being that it was always on the stem end 
of the fruit. 
On the majority of the fruits the infected area extended rather 
irregularly away from the torus, usually farther on one side (pi. 1, 
E), and often the lesion seemed to be caused by more or less separate 
invasions radiating from the torus. This was very apparent in 
early stages of the invasion when a few small blackened areas were 
found extending out from the torus. In some cases a rather large 
lesion extended out only from one side of the torus, and on some 
fruits the discoloration first appeared as a slightly sunken collar or 
circular row of separate lesions centered around the stem end at a 
distance of 1}^ to 2 cm (pi. 1,D). Sixteen out of 210 fruits examined 
showed this type of infection. Ordinarily the lesion did not involve 
more than one-third of the surface of the fruit, and no fruits with 
surface totally blackened were found. 
Owing to the radiating type of growth of the lesion, the margin 
tended to be irregularly lobed (pi. 1, A, C). Sometimes the margin 
was sharply defined, but frequently it was rather feathery (pi. 1, 
E) or the dark color blended rather gradually into the color of the 
apparently healthy part of the tomato (pi. 1, F). 
The lesions were usually distinctly black, the color being more or 
less solid on the green fruits, while on red fruits it could often be seen 
that it was due to a blackened subepidermal network (pi. 3, A). In 
the former case the margin was either sharp or fading, in the latter 
case it was feathery or fringed. In addition to the black discolora¬ 
tion there were two other conspicuous color reactions. Very fre¬ 
quently rather small, whitish, papery patches, due to air under the 
epidermis, occurred on the blackened areas (pi. 2, C); and bright 
yellow sunken areas occurred occasionally on red fruits, probably 
owing to an inhibition of red pigment formation. 
In the older lesions black raised subepidermal dots, very suggestive 
of pycnidia, occurred rather generally and were especially conspicuous 
fin the whitish patches and yellow areas. Occasionally there were 
noticed on a fruit narrow, wedge-shaped, whitish or light green super¬ 
ficial strips radiating out from the torus, with their narrow ends toward 
the torus, and with scattered black dots on them. 
Upon cutting longitudinally through the blackened stem-end 
lesions it was found that the entire thickness of the pericarp, as well 
as considerable portions of the locule walls and fleshy placental 
tissues, were involved in the blackening (pi. 2, D). Typically, there 
was no softening and very little structural disintegration of the 
affected tissues, but on the contrary these tissues were of a toughened 
spongy consistency. In some cases the blackened tissue could be 
torn loose and removed intact from the less coherent normal tissues. 
In other words, the affected tissues were somewhat mummified. 
Exceptions to this general condition were cases of secondary invasion 
of the killed tissues by bacteria. 
Usually" the internal blackening had penetrated somewhat further 
down into the placentae than in the pericarp or outer wall and was 
more extensive on the side showing the more external blackening. 
