ON THE GROWTH OF PLANTS. 39 



It s not a little remarkable that in both the Mangel and Kohl Rabbi the 

 results have been greater in the transplanted than in the untransplanted plots, 

 the former yielding a larger crop; this too has probably been favoured by 

 the moist season, but as it is a subject of great farming interest, we shall 

 renew our experiments upon this matter. 



Dipsacus fullonum et sylveslris. — Our plot of this year fully confirmed our 

 view of last year, as to the specific identity of these two forms of this plant; 

 for without being able to assert that we had decided D. fullonum from the 

 seeds of D. sylveslris, or the opposite, yet the specimens glided so imperceptibly 

 into either form, that, distinct as are decided examples, we were much puzzled 

 in deciding as to the paternity of some of our specimens. 



To quote from English Botany, 2nd edition : " Hudson mentions this plant 

 as growing about hedges. In the clothing countries, where it is cultivated 

 for use, it may escape from the fields. There is much doubt concerning the 

 value of its specific difference from the D. sylveslris." 



Bentham is of the same opinion, so that our experiments in this only lay 

 claim to a simple and practical method of confirming these views. Our 

 notion at the same time is that it would be exceedingly difficult to find a 

 wild example of the true D. fullonum ; that is, one which from its hard re- 

 flexed bracts would be worth anything for fulling purposes. We have hunted 

 long in the districts where the economic form of the Teasel is grown, and we 

 have always been of opinion that where its seed has been scattered and allowed 

 to grow wild, it lost its stiff hooked characters ; and, to say the least, even the 

 best of them merged into D. sylvestris ; the fullonum being indeed a difficult 

 plant to keep perfect, unless under constant change of seed and soil. 



Weeds, &c. 



Thistles have formed the subject of several experiments during the past 

 year, which will be referred to under the following names: — Carduus 

 arvensis, C. acaulis, vars., C. tuberosus. 



Carduus arvensis. — Our experiments upon the growth of this plant were 

 undertaken in order to explain their method of reproduction, as it had been 

 disputed by the farmer that thistles were produced from seed. 



On September 2nd, 1859, were sown ten seeds which had been collected 

 a few days previously ; by the 21st of the month these had all come up, and 

 some began to show the secondary leaves, as in Diagram, fig. 1. By the time 

 the prickly foliage became manifest, the cold weather had set in and all the 

 plants apparently died. However, in February 1860 we noticed a bud just 

 emerging through the soil, which induced us to take up a couple of the speci- 

 mens and make drawings of them, of which copies will be seen at 2 a and 2 b. 



Here then at a and b are buds by which the continuance of the plant is 

 secured, the buds a, b forming whilst b, b are sending up leaves for the second 

 year, so that by June the plants had advanced to the condition of fig. 3, in 

 which, while a strong shoot is progressing above ground, a most, extraordinary 

 rhizomation is taking place below fig. 3, fully explaining how in the next 

 season we may meet with a thicket of Thistles derived from a single plant. 



Here then it is obvious that the conclusions with respect to the Thistle not 

 seeding, were the result of the small and inconspicuous plant which it makes 

 the first year, and this apparently dying, confirmed this view ; however, we 

 see from this experiment that thistle seed is as fecundate as that of other 

 plants, and as we have counted as many as 150 seeds from a single head of 

 flowers, and as we may have an average of ten heads of flowers to a single 

 flowering stem, the eight tertiary buds at fig. 3 a, a may each represent a 



