24 
ammoniacal manure to the hind, cultivate early vegetables between the 
trees; then, after that crop is removed, sow the land in cow-peas. The 
result is bewilderiug. Next year the unfortunate planter is discouraged 
to find many of the trees dying back, the vegetable crop with knotty 
roots and irregular fruit. 
Another heavy fertilizing, another crop of peas, and that spot is done 
for. The disgusted farmer tries another vocation, and gives over the 
place to weeds and desolation. 
With young, closely-set rows of trees the disease causes greatest dam- 
age, spreading rapidly from tree to tree. 
In market gardens, especially the Tomato, Cucumber, Melon, and 
Squash, the Anguillula often either destroys the plants before fruiting 
or reduces the size of the fruit till it fails to pay expenses. 
A number of disastrous failures with gardens, that have come to my 
notice, no doubt resulted from this cause. 
LIFE HISTORY OF THE ANGUILLULA. 
The study of this microscopic worm has been exceedingly difficult, 
and many points in its history are not yet fully ascertained. 
The limit of its existence, periods of growth, sexual characteristics, 
generation, variation of form, and the precise action occasioning the 
abnormal growth in roots, are all undetermined questions which will 
take a long coutinued series of observations to solve. (Note 12.) 
As first observed, a mass of cells appears within the uterine cornua, 
cells averaging o-ooiro inch in diameter, arranged in bands from T oooo 
to toooo i Dcn i n width, reaching across to the walls of the uterus. 
/Plate XX, A, B.) These bands appear at the smaller end of the uterus, 
beginning from T tutVo to ro-Soo i ncn fr' om the free extremities, extend- 
ing downward -nfturo to jiftftfo inch. Lower down, these cells show a ten- 
dency to aggregate into irregular masses (Plate XX, B, 0), then into 
ovate forms, eventually becoming ovals t^Ioo by to~oVo inch. 
At first these cysts have no epidermis, but a thin coating appears 
and thickens as they approach the normal size of y^ooo i Llcu i 11 length 
and tA-oo i ucn i n width. (Plate XX, D, 2.) 
During the life of the female the cysts form rapidly, until the whole 
uterus becomes enormously enlarged, and contains cysts in every stage, 
from the primary agglomeration of cells to free Auguilluhe. (Plates 
XIX and XVIII.) 
The decay of the environing root exposes the pregnant female to 
changes in weather, and with a slight increase in heat the contraction 
of the exterior expels the contents of the uterus and disperses them. 
This in most cases appears to be through the upper segment, though 
often it occurs through the fissure in the head. (Plate XIX.) 
The cyst at first is a solid mass of granular cells. (Plates IX, 1, and 
X, 1.) It divides centrally at the shorter axis (Plates IX, 2, 3; X, 2, 
26, 4) ; each half repeats this process till four or five segments are visible- 
A longitudinal fissure then appears, causing eight segments (Plates 
