MICROSCOPY. 251 



In the April number of the Monthly Microscopical Jour- 

 nal is an interesting paper, by Professor Giovanni Briosi, of 

 Palermo, on the phytoptus of the vine. This disease, pro- 

 ducing protuberances, or cecidii, on the leaves, oftentimes 

 numerous and confluent, and, in fact, covering the whole leaf 

 convex on the upper and concave on the under side of the 

 leaves is due to punctures and irritation produced in the 

 texture by the acari, which lodge in the cecidium and live 

 on the leaf. The acari were termed phytoptus, to express 

 that they are really and solely parasites of living plants. 

 They are invisible to the naked eye, and the male cannot be 

 distinguished from the female with certainty. They have but 

 four legs, though Landois supposed that there were two other 

 (rudimentary) pairs, and that in their complete development 

 they possessed four pairs of legs, like other acari. Professor 

 Briosi considers that Landois is mistaken, and that these an- 

 imals constitute a special genus of acari which have only 

 four legs. These arachnida possess a most extraordinary 

 tenacity of life, moving the legs twenty-four hours after im- 

 mersion in glycerine. In the autumn they emigrate from 

 the leaves to nestle under the bracts which cover the winter 

 buds, and they have been found alive in buds which had 

 been exposed shortly before to a cold of 10 Fahr. In 

 the spring, with the swelling of the buds, the animals regain 

 their activity, and lay eggs, which are deposited directly on 

 the young leaves of the developing bud, and the young ones 

 are scarcely born when they find already within reach the 

 food which nourishes them ; and the galls, or cecidii, appear 

 under the form of small spots, scarcely raised, and of a slight- 

 ly different color from the rest of the leaf, but readily seen 

 by allowing the sunlight to shine through. Repeated care- 

 ful pruning of the stems Avhich showed the disease the pre- 

 ceding summer, and cutting off the attacked leaves, will, in 

 Professor Briosi's opinion, in a few years result in the de- 

 struction of this unwelcome visitor. 



In the Monthly Microscopical Journal for November, Dr. 

 Hinds calls attention to the motile protophytes in the leaves 

 of Hypericum androsoemum and H. calycinum. They are 

 to be found in the minute light -colored puncta3 near the 

 margin of the leaf, which are translucent from the absence 

 of chlorophyl. They are extremely active, and not of uni- 



