20 AMERICAN VINES. 



existing, although in very small quantity, even when the 

 vine is diseased, and this explains, no doubt, why secondary 

 branches can develop on primary branches even when all the 

 leaves are chlorotic. 



By way of compensation, in all the tissues there is an 

 abundance of crystals of salts of lime, oxalates, and tartrates; 

 the raphides are very abundant, so are the macles (caltrop 

 or chiastolite), etc., and often small prismatic crystals are 

 so abundant that they darken the microscope field. 



In short, chlorosis impoverishes the tissues of the vine in 

 all matters necessary for its existence, hence the active cells 

 so impoverished are badly constituted, suffer, and work 

 indifferently. The death of the vine may result, if the vine 

 is very sensitive to this affection (most of the Riparias, the 

 Vialla, and Cordifolia X Rupestris). 



A given variety of vine is not equally subject to chlorosis 

 at all periods of its existence. In soils where soil and sub- 

 soil are both very calcareous (chalky soils of Champagne 

 and Charentes, and white Miocene marls of the south of 

 France, etc.), a vine begins to turn yellow the first year of 

 planting out, in August, September, or October, while up 

 till that it had remained green. 



The next spring the first shoots soon turn yellow, and the 

 yellowing is somehow the continuation of the intensity of 

 that of the previous year, and increases more and more till 

 June or July. From that time forward the leaves often 

 become green again till at the end of autumn they have 

 completely turned to green. Then, the third year, chlorosis 

 appears later on, the first shoots being green. It is only in 

 May or June that they get chlorotic again, but to a smaller 

 degree than in the second year. They also become green 

 sooner, and it is not uncommon to see them completely green 

 in August, or at the latest in September. The following 

 years chlorosis only shows itself during a short period, almost 

 always at the end of May or June, and during very rainy 

 years, and does not involve grave consequences in the vegeta- 

 tion of the vine. 



This order of things always takes place in the same way 

 with European vines, and even, but with slighter differences, 

 with the less sensitive to chlorosis of the American vines 

 such as Berlandieri and* Franco-American hybrids of 

 Berlandieri, Riparia, Rupestris, etc. 



The second year chlorosis may be so intense on certain 



