142 DEPARTMENT REPORTS. 



a little sulphur-colored, while those of Ghardon are violet-rose or rose-violet. 

 The tubers from these white-flowered plants differed from those of the type 

 in being more round and regular and having less pronounced eyes. Aside 

 from these variations we have found among the Chardon both earlier and 

 later varieties, and this in spite of the fact that we had planted only such 

 tubers as appeared to be entirely true and which for a long time had produced 

 no variations whatever. Here, as in the preceding cases, the modifications 

 were from the tubers, seed not having been sown. 



" An instance similar to the above is reported by M. Joigneaux in the 

 Journal de la Ferine et des Maisons de Gampagne : Nine or ten years ago six 

 beautiful tubers of a long, pale yellow potato were given us. In order to 

 increase the number of hills we divided each tuber into three pieces. We 

 planted them ourselves. The cultivating was also done by us. Some of the 

 potatoes, a very small number, resembled the type, but the larger number 

 were spherical, some yellow like the parent, others deep red. 



" All cultivators know that the smooth or even Vitelottes, whose eyes are 

 few in number and scarcely perceptible, often produce tubers of various 

 forms and with eyes so much sunken that it is almost impossible to peel them. 

 Once we obtained a variety which, besides of the many and deep eyes, 

 produced, in considerable quantity, agglomerations which gave to the 

 whole a monstrous form. They were veritable hydras. Although coming 

 from the Vitelotte, which is a good potato, this variety was very acrid and 

 bad. 



" All these examples show without any doubt how a large part of the varie- 

 ties of potatoes are produced, and proves that they do not all come from 

 seeds. We shall convince ourselves of it when, having observed the growth 

 of the plants, we mark the peculiar plants and gather separately their 

 tubers. An external modification is always the consequence of an internal 

 modification. 



"The phenomena presented by potatoes prove that the cause of the appear- 

 ing of new varieties is not always due, as we generally suppose, to crossing, as 

 fecundation can act only upon the seeds. It is also very rarely that we practice 

 crossing in potatoes, but we can number the varieties by the hundred. But it 

 often happens that cuttings made from portions of the top of the plant pro- 

 duce varieties different from the parent. Moreover, the existence of numer- 

 ous varieties of certain plants which we cultivate and which never produce 

 seeds, proves beyond a doubt that there are causes aside from crossing which 

 tend to the production of new varieties." 



3. Notes on crossing and hybridizing. — There has been much discus- 

 sion of late as to whether the effect of foreign pollen is visible in the fruit 

 of the current year. In order to satisfy myself upon this and other points, 

 an extensive system of experiments was planned. A lack of time to give 

 the matter personal attention made the investigation impracticable, however, 

 and I have to report but a few isolated experiments. These few were per- 

 formed in the most careful manner possible. The flower buds were opened 

 and the flower emasculated before any pollen could have reached the stigma. 

 The pollen was also secured from flowers which were still in the bud, or 

 which had been covered to exclude all foreign pollen from falling upon the 

 anthers and becoming mixed with the pollen intended for use. The pollen 

 was applied to the stigma by the aid of a thin knife blade. I have never 

 used a camel's hair brush, so often recommended, from the fear that foreign 



