The Phytoptus of the Vine. By Prof. Giovanni Briosi. 189 
unless pronouncing males all animals in which no eggs can be 
discovered. 
Sorauer, and before him Scheuten, found in the Phytoptus pore 
animals of two distinct forms, that is, besides those cylindrical ones 
described here, others larger in front and round like egg ‘tops 
(Spitzeirunde), which were supposed to represent the male form in 
complete development. On the vine, however, I never could see 
any other but the variety of the cylindrical form, and Landois too 
seems only to have found this one, as he does not speak of an 
other. The animal of Figs. 11, 12 (laterally and in front), with 
valve entirely shut, may be to my mind either male or female, in 
which no eggs can be discovered. 
Once I had the opportunity of observing very closely the 
esophagus, the beginning of which is seen in n, Fig. 5; it is a 
tube with a very thin coat, which, as it descends, is enlarged to a 
kind of small bladder or bag, which is seen at the back part, 
towards the dorsal (at the same height about as the genital organs), 
which must take the place of the stomach. The intestines, how- 
ever, are lost below the stomach, and sometimes only the last part, 
ending at the anus, reappears. 
In the abdominal region there are often found oval corpuscles 
of various sizes, the largest in front, the smallest behind ; all con- 
tained in an oblong tube or bag, which ends in the genital valve 
on one side, and extends towards the anus on the other. The first 
are eggs in various stages of development, the second the ovary. 
The eggs are discharged by the opening of the valve (a, Figs. 2, 3), 
and I believe I have caught an animal in the very act of ex- 
pelling matured eggs, pretty far out already, as seen in Figs. 2, 3, 
representing the said animal laterally and in front. 
The ovary occupies the abdominal region, viz. nearer the 
abdominal surface than the dorsal (contrary to the intestines), and 
in the fore part, where the most developed eggs are, it seems to fill 
up nearly all the internal cavity of the animal. 
In the cecidozoid of Figs. 4, 5, the ovary was seen partly 
hanging out of the body, which was torn from above. The eggs 
when leaving the body are covered with a glutinous substance, on 
account of which they adhere to the objects on which they fall. 
Thus they are often found laterally suspended from the hairs C, 
where the mother must have deposited them. The egg has a 
somewhat elongated shape, and its contents when leaving the body 
of the mother appear uniform and finely granulated (Fig. 6). As it 
increases in volume one begins to distinguish in the interior a 
centre line (Fig. 8), afterwards the roundish shape of the outline 
of the embryo (Fig. 7); and even before breaking the vitelline 
membrane one can perceive inside already the animal rolled up in 
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