130 
STRAWBERRY. 
Dr. Ritzema Bos observes tliat “ this Aphelenchus frag aria is a 
small species” (the greatest length of such small amount of males 
and females as occurred in the plants I sent was found by him to be, 
of males, 0-85 mm.; of females, 0-80 mm.— Ed.). “The stilet is 
small; in one specimen I decided it to be 0-0094 mm. long. Although 
this organ is at first sharp and thin, it ends in a blunt knob-shaped 
swelling.* The gullet was indistinct in the specimens I examined; 
it seemed to be rather twisted. The sucking stomach is oval; there 
the intestine begins, at first very narrow, afterwards broader. Its 
wall is finely granulated.” Details are given of male and female 
characteristics, so far as observable ; but though larvae were plentiful 
in the plants I forwarded in May and June, yet Dr. Ritzema Bos 
noted with regard to the males and females :—“ I did not observe one 
of either sex which was perfectly mature, containing developed 
spermatozoa or eggs on the point of being laid. It seems from this as 
though reproduction only takes place during the latter part of 
summer.”—(J. R. B.) 
The following extract describes the effect of the infestation on 
various parts of the plant, as the stems, buds, flower petals, calyx, &e., 
and being favoured with permission so to do, I give it in the words of 
Dr. Ritzema Bos rather than my own, as being clearer and much 
more technically precise than any wording I could myself have 
offered. 
Description of the effects of the infestation on the growth of the 
Strawberry plant. 
“In the axils of the normally developed lower leaves (see Plate, 
fig. 1, h) numerous thick scaly buds appear, much like the little scales 
that form on a bulb ; these buds never grow new stolons. Sometimes 
the main stem grows fairly tall to begin with (probably because the 
plant was not attacked by a large number of Aphelenchus at once), but 
a certain height being attained, it branches very vigorously, and the 
branches are not only thick and broad, but remain united as they 
grow, so that there is actual fasciation. There is, however, no ribbon¬ 
like broadening, but a thickening, which can be best compared to a 
piece of Cauliflower; therefore I have indicated the disease caused by 
Aphelenchus frag aria as ‘ Cauliflower disease of Strawberry plants.’ 
“In a few cases a simple ribbon-like broadening of the stalk takes 
place, and the numerous flower and leaf buds that result are more or 
less normally developed. Sometimes one side of the stalk or branch 
grows and fasciates more strongly than the other side; the stem then 
* If the reader will turn to Plate of T. devastatrix, he will see a spear or -stilet 
with knob-shaped base figured at “a” in 1 and 4, which gives an idea of the form 
of this mouth part, but with the difference that in the Tylenchus this knob is 
trilobed, 
