28 
Journal of Agricultural Research 
Vol. XI, No. i 
The illustrations have been very carefully prepared, and with their aid almost any 
careful microscopist should be able to identify the species. For this purpose it is 
advisable to use living specimens under sufficient pressure to prevent active motion. 
This method will give somewhat exaggerated width measurements, for which due 
allowance should be made. To see all the features shown, requires the use of an 
immersion lens under favorable conditions. 
Fig. i. — Tylenchus penetrans; Adult female. It is believed that the 
glands, gl sal, empty into the pharynx via the esophagus, as in Ty¬ 
lenchus similis , but the full details of the structures have not been 
worked out in T. penetrans, ac, accessory piece to spicula; al, wing of 
cuticle; an, anus; 6/6 oe, median esophageal bulb; 6/6 on, bulbs of the 
spear; brs, bursa; cav som, body cavity; cl ren, cell of the renette; cl 
ut , one of the cells of uterine wall; cst brs, ribs of bursa; cut, cuticle; 
dct ren. duct of the renette; exp, excretory pore; gl sal, “salivary" 
gland; ini, intestine; ini grn, granule of the intestine; lb, lip region; 
him oe, lumen of the esophagus; lum on, lumen of the spear; msc bib, 
radial muscles of bulb; msc on, protruding muscles of the spear; 
msc som, somatic muscle; ncl nrv, nucleus of nerve cell; ncl ren, 
nucleus of renette cell; nrv r, nerve-ring; oe, esophagus; on, spear; 
on dir , guiding apparatus for spear; or, mouth; ov, ovary; ret, rectum; 
sp, spiculum; sub cui, subcuticle; %rm, terminus; ut, uterus; ut post 
rud, posterior rudimentary 
uterus; vag, vagina; vlv, vulva. 
This specimen is mature, but 
has not yet begun to deposit 
eggs. The empty uterus indi¬ 
cates that the specimen is prob¬ 
ably a virgin female. 
X750 
