182 The Phytoptus of the Vine. By Prof. Giovanni Briosi. 
which, thus attacked, have not a single spot left healthy and 
uncovered. 
Convex on the upper and concave on the under side of the 
leaves, these parasites present themselves covered with minute 
hairs, whitish in spring, later on reddish, or of a more or less dark 
tobacco colour. 
Fig. 1 represents a vine leaf slightly diseased, seen from 
beneath where the galls appear concave. : 
On the upper side the galls retain in the beginning the green 
colour of the leaf, turn yellowish later on, and become even brown, 
according to the force of the disease or the variety of the vine. 
Malpighi thought that the galls were caused by the drops of 
a liquid which he saw deposited by insects on the leaves together 
with eggs, and to which liquid he ascribed a fermenting action. 
Afterwards Malpighi’s explanation did not seem satisfactory, and 
many naturalists studied the phenomenon of the galls of the 
plants, amongst whom Persoon, Fries, Réaumur, Unger, Schlech- 
tendal, Fée, Lacaze-Duthiers, Vallot, Pagenstecher, &c.; and also, 
in the past few years, Landois, Thomas, and Sorauer published 
most important works on this subject.* 
Most of them at first saw in the contents of the galls parasitic 
fungi, and thus were created the genera Taphrina, Hrinewm, and 
Phyllerium. 
Palissot de Beauvais believed them algx, and Unger enlarge- 
ments of the leaf cells; others, directly enlarged hairs. 
* Publications —Malpighi, On the Excrescences and Tumours in Plants; 
Persoon, Sinops fungor, 1809; Fries, Observat. mycolog. 1815; Idem, Syst. 
mycologicum, 1825; Schlechtendal, Denkschrift der botan. Gesellsch. in Regens- 
burg, t. ii. 1822; Idem, Botan. Zeitung, t. xxiv.; Réaumur, Mémoires pour servir 
a 'Histoire des Insectes, 11. Mem. ix.; Vallot, Med. Acad. Dijon, 1832, part. d. 
scienc.; Unger, Die Exantheme der Pflanzen, 1833; Duges, Annales des Sciences 
naturelles, 2™¢ série, t. ii. 1834; Fée, Mémoire sur la Groupe des Phylleriées de 
Fries, 1834; Lacaze-Duthiers, Recherches pour servir 4 Histoire des Galles, 
Annales des Science. nat. 3° série, Bot. t. xix. 1853 ; Dujardin, Annales des Sciences 
nat. 8° série, t. xv. 1857; A. Scheuter, Troschl’s Archiv fir Naturgeschichte, 
Jahreang 23, t. i. p. 104, 1857; Pagenstecher, H. A., Ueber Milben, besonders 
die Gattung Phytoptus, in Verhandl. d. nat.-med. Vereins zu Heidelberg, t. i. 
1857-59 ; Landois, H., Eine Milbe (Phytoptus vitis mihi) als Ursache des Trau- 
benmisswachses, in Zeitschrift fiir wissenschaftliche Zoologie von Siebold und 
Kolliker, t. xiv. p. 353, and following ones, 1864; Landois and Roese, Bot. Zeit. 
1866, No. 38, p. 293; Thomas, Fr., Ueber Phytoptus Duj. und seine grossere 
Anzahl neuer und wenig gekannter Missbildungen, welche diese Milben an 
Pflanzen hervorbringen, con. I. Tay. in Prog. d. Realschule zu Ohrdurf, 1869 ; 
Idem, Schweizerische Milbengallen, Verhandlungen der St. Gallischen naturw. 
Gesellschaft, 1870-71; Idem, Milbengallen und verwandte Pflanzenauswiichse, 
in Bot. Zeit. 1872, No. 17, p. 282, and following ones; Idem, Entwicklungs- 
geschichte zweier Phytoptus-Gallen an Prunus, in Giebel’s Zeitschr. f.d. ge- 
sammten Naturwissenschaften, t. xxxix. p. 193, and following ones, 1872; Idem, 
Beitriige zur Kenntniss der Milbengallen und der Gallmilben; Idem, Die 
Stellung der Blattgallen an den Holzgewachsen und die Lebensweise von Phy- 
toptus (Zeitschrift f.d. gesammt. Naturwiss. t. xlii. pp. 513-537, 1873) ; T. Moritz, 
in Frauendorfer Blatter, p. 30, 1873; Sorauer, P., Handbuch der Pflanzenkrank- 
heiten, Berlin, 1874, p. 165, and following ones, 
