278 PLANT BREEDING. speak, at the production of hybrids, the curious and experimenting gardener has calmly plodded on, mixing one species with another, oftentimes hap-hazard, and quite regardless of the confusion he was creating. One after another long cherished ideas of the botanist were shattered by the results of " crossing," and now a stage has been reached when it is impossible for anyone to say what may not happen. The partitions between what are termed varieties, species, and genera have all been broken down by the hybridist, and although the botanical world may have been thrown into confusion thereby, gardeners feel rather proud of their achieve- ments — at the way in which they have as it were marked out certain courses for nature to follow blindly. Of course, as Prof. Bailey points out, the hybridist must have some knowledge of the affinities of plants before he can hope to produce any results by transferring the pollen from one flower to the stigma of another. It would never do, for instance, for him to attempt to produce a hybrid between a grass and rose. '* The notion," says Prof. Bailey, " is somehow firmly rooted in the popular mind that new varieties can be produced with the greatest ease by crossing parents of given attributes. There is something captivating about the notion. It smacks of a somewhat magic power which man evokes as he passes his wand over the untamed forces of nature. . . . Man must not only practice a judicious selection of parents, but he must constantly select the best from among the crosses in order to maintain a high degree of usefulness and to make any advancement." There is the art of raising new plants in a nutshell, but it comprises a great deal more knowledge on the part of the gardener than appears on the face of it. The various circumstances which tend to the production of good hybrids are fully and lucidly discussed by Prof. Bailey, and his advice as to what to aim at and what to avoid is good, in- asmuch as it will save the gardener who reads his book a great deal of time and disappointment. It would, for instance, be sheer waste of time and energy for one to attempt to raise hybrids from parents which have been crossed over and over again by other operators without result, in the vain hope that somethinr/ would be produced. In the case of Solanums, Prof. Bailey points out that some naturally produce tubers, and others are more adapted for fruit. It would be unwise to breed between tuber and fruit-bearing varieties. ** Those ambitious persons who are always looking for a tuber-bearing tomato, therefore, might better concentrate their energies on the potato, for the tomato is not developing in that direction ; and even if the tomato could be made to produce tubers, it would thereby lessen its fruit production, for plants cannot maintain two diverse and profitable crops at the same time." These few extracts will give a faint outline of the information contained in Prof. Bailey's book, which is essentially one for the gardener. The copious index shows what a large number of plants have been brought under the control of the hybridist, and will serve' as a valuable guide to would-be operators in this interesting department of plant development. J. Weathers.
