dull-prtxluciiKj AiiijiuHiiIk/c. '.\A)\ 



arc at first comparatively thick, firm, and tull of sap ; but 

 towards autumn thoy <j^radually become tliinner, less juicy, 

 and wriuklt.'il in folds, whilst their colour at the same time 

 gradually changes to yellowish green. Two or three of tiiese 

 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 open 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. Tiiis whitish 

 lump, when brought into contact with a drop of water, quickly 

 flows asunder ; and we then see, under the microscope, hundreds 

 of Anguillulai in all stages of development, twisting about one 

 over the other with slow movements. 



As in all known Anguillulai of plants, the extraordinary 

 vitality of this species after desiccation for months is very 

 remarkable. I tested tliis 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 

 Anguillulai, 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 life 

 is confirmed by most authors. Dr. Julius Kiihn, who dis- 

 covered Anguillula di'psaci in the inflorescence and fruit of 

 Dipsacus Jvllonunij MilL*, found that this species came to 

 life again when moistened with water after eight months' de- 

 siccation in a heated room. Bauerf states the duration of the 

 capacity of revivification in Anguillula tritici at eight years. 

 Baker| found that the young oi Anguillula tritici 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 Anguillulai possess in common with 

 the Tardigrada and Rotatoria, was already known to Linne§. 



But reviving as is the eiFect of moistening with water upon 

 the dried Anguillulje, 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 



* Zeitechr. fiir wiss. Zool. Bd. ix. (1858), p. 129. 



t .\nn. des Sci. Nat. tome ii. (1824), p. 154. 



X Lettre de Xeedham en reponse an Memoire de Roffredi dans le 

 Journal de Physique de I'Abbe Rozier, 1775, p. 227. 



§ Linne says of the Anguillula? of vinegar and paste (Syst. Nat. ed. xii. 

 torn. i. p. 182(3) : — ''Chaos : Corpus liberum, unifomie, redirivum, artubus 

 sensusque extcmis nullis. 1. Ch. redt'vt'vum, filiforme, utrinque attenu- 

 atum ; habitat in acoto et glutine Bibliopegorum. Reviviscit ex aqua per 

 annos exsicpatmn ; oviparum vel vivipariwn." 



24* 



