'»*'• DR. WEISMANN'S THEORY OF HEREDITY. 175 



actually produced and visible in the first season. He thus describes 

 his results: — "In the spring of 1848 I planted two of my experi- 

 mental plots 5 with seeds of Pastinaca sativa and Daucus carota. The 

 seeds were gathered in the previous summer from wild plants. In 

 the autumn, whilst most of the specimens presented the dark green 

 hairy leaves peculiar to the wild plant, there were a few examples in 

 which the foliage had assumed the light green and smooth aspect 

 devoid of hairs which characterises the cultivated plant, and among 

 the latter there were a few with larger leaves and broader divisions, 

 or leaf-lobes, than the rest, the leaves, too, all growing symmetrically 

 around one central bud. The roots of the plants taken up were 

 observed to be, for the most part, more fleshy than those of the wild 

 examples." 



In the spring of 1849, the reserved roots were dug up, and the 

 best put aside for transplanting. Late in the summer of 1849, the 

 seed was collected, and sown in 1850. 



The result of the second sowing was that the leaves in all indi- 

 cated an advance to the cultivated form. Some specimens were much 

 finer than others, of good size, and with a tolerably smooth outline.^ 



" In the case of carrots of the first crop all the specimens mani- 

 fested a disposition to send up several heads, and most of them ran 

 to seed. The roots were much forked, and but little inclined to 

 increase the tissue. The second crop was certainly improved, the 

 crowns of many displayed but one bud. The roots became more 

 succulent and enlarged." 7 



This experiment seems to justify my remarks, for it is evident 

 that all the plants, both of parsnips and carrots, were not equally 

 affected by the new environment, and while in some the changes 

 were " visible " at once, in others, especially the carrots, it required 

 a generation to evince them satisfactorily. The probability is — 

 judging from the pronounced way in which some were modified — 

 that all were more or less influenced, and had Professor Buckman 

 examined the tissues of the roots he might possibly have detected 

 the commencement of hypertrophy in the first season in every one. 



As another instance of experimental evidence, I will refer to that 

 of M. Lesage upon maritime plants. It is usual to attribute the 

 fleshy character of the leaves of several maritime plants to their 

 growth by the seaside, where salt can reach them ; and that salt is 



5 In the garden of the Agricultural College, Cirencester, at which he was the 

 Professor of Natural History. 



8 Professor Buckman called one "The Student," a hollow-crowned form, and 

 forwarded seeds to Messrs. Sutton & Sons to grow ; they approved of it, and issued 

 it as "Improved," in 1851. On writing to them in 1890, they informed me that 

 they still consider it the "best variety" in their stock. Hence it has been now 

 established in the trade for 40 years. In 1891 they issued a new illustration of 

 "The Student," which shows marked differences from that drawn in 1861. 



' Journ. Agricult. Soc, England, 1864. 



