F. J. Chittenden 3:31 



the realms of the plant-physiologist, and he may better call to his aid 

 the mycologist to make a s])ecial study of the parasite, and the student 

 of plant-relationships and plant-breeding, than that the mycologist 

 should call in the aid of the physiologist. The physiological is the larger 

 problem, and the mycologist should look upon his special task as a 

 branch of the })hysiological problem. He should, indeed, view his task 

 from the physiological standpoint, and l)ase his work upon a thorough 

 knowledge of physiology. 



It is clear that even so far (and this is not all) the problem is one that 

 calls for team work, for no one man can hope to tackle by himself all 

 sides of the problems involved, though one man here and there may be 

 able to co-ordinate the results of all the many lines of work that need to 

 be followed up. 



The points so far touched upon are general but there are some special 

 to horticulture, and they on the one hand help to minimize the special 

 difficulties of that art and on the other to increase them. The conditions 

 of cultivation in the garden are, on the whole, more under control, and 

 more artificial (in the sense that they are more "made") than in agri- 

 culture or forestry. They are therefore more capable of modification 

 than are those of the field or the forest. The horticulturist aims to secure 

 very large returns from a given area as compared with the agriculturist: 

 his methods are intensive. Furthermore the agriculturist grows only a 

 few adaptable kinds of plants and these in great numbers, while the 

 horticulturist grows many kinds and necessarily attaches great import- 

 ance to the well-being of every individual ; many of these kinds, too, are 

 of limited adaptability.- The horticulturist's work entails the frequent 

 removal of growing plants from place to place, sometimes over long 

 distances, and thus increases the danger of carrying disease from place 

 to place. The guarding against the contraction of disease is not so de- 

 pendent upon one individual's efforts as in agriculture — it is dependent 

 upon the vigilance of several independent persons and the dangers are 

 therefore multiplied. 



The task before the individual who attempts to integrate the results 

 of mycological research with horticultural practice are therefore, in 

 any particular case, on the one hand easier and on the other more difficult 

 than in agriculture. He must devise methods of avoidance or of securing 

 absolute immunity which all concerned may be able to adopt, or of 

 preventing attack in the presence of danger, or of lessening the damage 

 in the case of an attack ; and in addition he must bear in mind that the 

 treatment must be economical and such as the crop will bear. That is 

 to say, the cost of treatment must be such that the increase in value of 

 the crop resulting will more than balance the extra outlay. 



