the Potato Disease, d-c. 195 



and the soil has become exhausted of the peculiar elements 

 essential to the reproduction of the plant. Tlie extraordinary- 

 success with which its cultivation is attended in fresh virgin 

 soil, such as a new colony affords, sufficiently attests this point. 

 The poverty of ^the people of Ireland has increased with 

 their numbers, while their means of cultivating to the best 

 advantage has diminished in an opposite ratio : again, this 

 pressure upon the poorer and most numerous class of 

 cultivators has tempted them to rear inferior varieties of 

 the plant — such as the " lumper," the " ox-noble," and other 

 cattle potatoes. 



I think that the frequent repetition of these years of 

 scarcity and famine serve to point to a still different cause of 

 failure : one having even a more general influence, as affect- 

 ing more intimately and vitally the plant itself — one which 

 scarcely appears to have been noticed, except by some of 

 the more distinguished horticulturists — one which we more 

 especially have it in our power to assist in obviating, and 

 to which, therefore, I would particularly draw the attention 

 of members of this Society. It is now pretty well established 

 as a law in cultivation, that there is a point beyond which 

 it cannot be carried without occasioning the plant or flower 

 to produce monsters, or to become unhealthy and die off. 

 This is particularly the case in plants propagated by offsets, 

 grafts, or from the roots. Where a new progeny is pro- 

 duced from seed, the cause of failure is not so apparent ; 

 the cereal plants, which have been cultivated for thousands 

 of years, seem to possess the same fecundity as ever. Nations 

 living on rice, and which has been their diet beyond all 

 record, — India and China for instance, — are not subject to 

 loss of crop, and their staple article of food, so frequently as 

 the Irish. The gardener knows full well that, in the case 

 of apples, the old sorts — such as the golden pippin, the 

 nonsuch, the pearmain — have disappeared ; and there is 



