Lloyd-Jones: What is a Breed? 



537 



an association was formed for their 

 registry. But it soon developed that 

 more than one kind of draft horse 

 existed in France and that a motly 

 array of horses was being offered for 

 entr}^ into the American book. A bitter 

 dispute arose concerning cHgibiHt}'' of 

 horses for record. All admitted that a 

 bre?i exist sd, but no one could give a 

 satisfactory definition of a piire-hred. 

 Finally in 1883, acting on the insistent 

 requests of American importers, the 

 French breeders established a Record 

 Association. They accepted as founda- 

 tion animals onh^ those draft horses 

 found in the six provinces which com- 

 prised the old district of La Perche. 

 At once American breeders stipulated 

 that imported horses, to qualify for 

 entrance in the American Association 

 books, must first be accepted by the 



French Society. This ended the em- 

 barrassing uncertainty ; a breeder could 

 now lay claim to the title "pure-bred" for 

 a horse and could successfully estabHsh 

 his right to do so. Pure-breds were 

 created by definition as a residt of this 

 action by the Society. But though the 

 sale value of these horses was greatly 

 increased, their biological nature was 

 not changed. This word again depends 

 for its meaning on the verdict of a body 

 of men; it is in fact a civil, rather than a 

 biological word. Biologically a horse 

 may carry enough heritable traits to 

 make him a high caste pure-bred 

 Percheron, but if his ancestors lived 

 across the line in Boulogne rather than, 

 in one of the six provinces originally- 

 specified by the French rules committee, 

 he cannot claim that title, but must 

 remain a Boulonnais. 



Studies of Citrous Fruits 



Study of citrous fruits at the California Agricultural Experiment Station has 

 convinced the investigators that : 



L In all natiu-ally fertile varieties of orange trees, self-pollination is the rule and 

 cross-pollination unnecessary. 



2. Viable pollen is either wanting or very scarce in parthenocarpic varieties — i.e., 

 varieties which produce fruit without seeds; the navel orange, for example. 



3. The time required for complete fertilization after pollination varies with the 

 variety from thirty hours in the Satsuma orange to four weeks in the wild Citrus 

 trifoliata. 



4. Normal embryo sacs are occasionally produced in the Washington Navel and 

 Satsuma oranges. If such oranges happen to be pollinated with viable pollen 

 from a nearby fertile variety, the result is the production of a few seeds in a navel 

 orange. In other cases, even if pollination should take place, no seeds are pro- 

 duced because the embryo sacs in the navel orange disintegrate. In other words, 

 navel oranges are seedless in most cases merely becavise they are not effectively 

 pollinated and yet are able to produce fruit without such pollination. 



Finally, the investigators have come to the conclusion that the origin of partheno- 

 carpic citrus varieties — the navel orange, the seedless pomelo, etc. — is to be found 

 in hybrids between naturally fertile varieties. The same explanation has been 

 given for the seedlessness of the commercial banana and many other fruits. Such 

 a theory, if it can be developed, opens the way for the commercial production of 

 seedless fruits in many species where simple selection would be of little practical 

 value. Extensive hybridization work is being taken up in citrus, while the study 

 of purity of varieties has also received attention. 



