Gall-producing Anguillulide. 343 
are at first comparatively thick, firm, and full of sap; but 
towards autumn they gradually become thinner, less juicy, 
and wrinkled in folds, whilst their colour at the same time 
gradually changes to yellowish green. ‘Two or three of these 
galls often occur upon one leaf, by which the latter is greatly 
deformed, as each gall causes an angular bending or twisting 
of the axis of the leaf. 
If we cpen one of these inflations we see in its interior, 
with the lens, a soft whitish lump, surrounded and penetrated 
by a greenish yellow, somewhat viscous fluid. This whitish 
lamp, when brought into contact with a drop of water, quickly 
flows asunder ; and we then see, under the microscope, hundreds 
of Anguillule in all stages of development, twisting about one 
over the other with slew movements. 
As in all known Anguillule of plants, the extraordinary 
vitality of this species after desiccation for months is very 
remarkable. I tested this tenacity of life, by taking a leaf 
bearing galls, collected in May and dried for my herbarium, 
and moistening it in October. Within a few hours all the 
Anguillule, which had been dried in it until they were quite 
brittle, were again lively. Even those which are repeatedly 
dried upon the object- -slide of the microscope waken to new 
life after each moistening. This remarkable tenacity of lite 
is confirmed by most authors. Dr. Julius Kiihn, who dis- 
covered Anguillula psa in the inflorescence and fruit of 
Dipsacus fullonum, Mill.*, found that this species came to 
life again when moistened ‘with water after eight months’ de- 
siccation in a heated room. Bauert states the duration of the 
capacity of revivification in Anguillula triticé at eight years. 
Baker} found that the young of Angutllula tritict enclosed in 
diseased grains of wheat could be revived even after a desic- 
cation of twenty-seven years, by moistening with water; and 
this property, which the Anguillulz possess in common with 
the Tardigrada and Rotatoria, was already known to Linné§. 
But reviving as is the effect of moistening with water upon 
the dried Anguillule, remaining in it is equally injurious to 
them ; for although they cannot exist without a certain amount 
of moisture, they die in water usually within a few days, as 
* Zeitschr. fiir wiss. Zool. Bd. ix. (1858), p. 129. 
+ Ann. des Sci. Nat. tome ii. (1824), p. 15. 
t Lettre de Needham en réponse au Mémoire de Roffredi dans le 
Journal de Physique de Abbé Rozier, 1775, p. 227. 
§ Linné says of the Anguillulz of vinegar and paste (Syst. Nat. ed. xii. 
tom. i. p. 1526) -—“Chaos: Corpus liberum, uniforme, redivivum, artubus 
sensusque externis nullis. 1. Ch. redivivum, filiforme, utrinque attenu- 
atum ; habitat in aceto et glutine Bibliopegor um. Reviviscit ex aqua per 
annos exsiccatum ; oviparum vel viviparum.’ 
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