170 Report oF THE BOTANIST OF THE 
duce dealers who were accordingly suspicious of all onions coming 
from Orange Co. The same rot was also common in the onion 
fields of Madison Co., but the losses from it there were not nearly 
so great as in Orange Co. © | 
The rot was of two kinds: (1) One which starts at the bottom 
of the onion, and (2) One which starts at the top or “ neck.” 
The latter kind of rot was much the more common, constituting 
perhaps eighty per ct. of the total amount of rot. Where the rot 
had started at the top the bulbs were frequently sound in ap- 
pearance, but rotten within. Oftentimes it was difficult to deter- 
mine, before cutting, whether or not a bulb was rotten. In sort- 
ing, the customary test for soundness was to press down with the 
thumbs close about the “neck” of the onion. If it was hard the 
bulb was sound, but if soft it was usually rotten inside. Onion 
growers speak of such onions as being “‘ weak in the neck.” Upon 
cutting open the affected bulbs it was generally found that two or 
three of the outer scales were perfectly sound while the remainder 
of the bulb was a rotten mass. Frequently a single scale would 
be. entirely rotten from top to bottom and clear around the bulb, 
while the remaining scales upon both sides of it, were perfectly 
sound. Such specimens cut crosswise showed the rotten part in 
the form of a ring. (See Plate X.) Again, a perfectly sound 
scale would be found between two rotten ones. (See Plate XL.) 
The rot appears never to spread from one scale to another later- 
ally, and this peculiarity furnishes the most reliable means for the 
identification of this rot. The organism causing it is unable to 
pass through the uninjured epidermis of the scale. The passage 
from one fleshy layer to another is effected at the base of the,bulb 
where they unite. Upon reaching the base of the scale in which 
it is working the rot commonly stops, and this accounts for the 
large number of cases in which one or two scales are rotten while 
the remainder of the bulb continues sound. Under certain con- 
ditions the rot does not stop at the base, but works its way into the 
bases of other scales which it then follows upward destroying the 
whole bulb. 
