801 SHORT NOTES AND QCERIES.
it happens Avith Willows less frequently than is generally supposed. I was surprised, therefore, to come upon a passage in Linnaeiis's ' Anta?uitates Academirae ' (vol. i. p. 100), which speaks of the seminal fertility of Willows and Poplars as a thing to be guarded against. " Ambulacra ex Popnlo vel Salice formare cupiens, solos mares assumat ; si enim feinina? terrae mandentur, multiplicantur, ita ut neinus loco ambulacri forment." The advice, however, might merely be an as- sumption deduced from the trees being monrecions. It may, perhaps, be a piece of evidence on the other side that De Candolle (' Physiologic Vciietale.' ii. 734) remarks, ' Nous posscdons depnis pen les deux sexes dn Saule plenrenr (voyez Spenner, PI. Prib. iii. p. 1061), raais lis n'ont pas encore produit de graines." However, that Willows are hybridizable is proved by the existence of a book, by Max Wichura, entirely devoted to the experimental investigation of the subject (' Die Bastardbefruchtung . • . der Weiden,' ISfio). Mr. Darwin, quoting from it, remarks in the 'Origin of Species' (4tii ed. p. 813), "It is known that hybiids raised from very distinct species are sometimes weak and dwarfed, and perish at an early age, of which fact Max Wichura has recently given some striking cases with hybrid Willows." And in his 'Animals and Plants under Domestication ' (vol. ii. 267), he mentions that " Max Wichura united six distinct species of Willows into a single hybrid" (by successive crosses). — W. T. Thiselton Dyeii.
I noticed about a month ago in one of the tlower-beds, which occupy the site of the old reservoir near Grosvenor Gate, Hyde Park, a single seed- ling plant of Salix (Jr/prea, L. This was then about a foot high. 1 did not think from its appearance and regularity of growth, vertical as well as lateral, that this could be a willow-cutting which had been stuck in to protect some young plant, and which had subsequently taken root on its own ac- count. But the plant is easily found if any l)otanist cares to investigate the subject further, as the site of the old reservoir does not occupy many roods of around. — J. L. Warren.
��Middlesex Plants. — Between Primrose Hill and King Henry's "Road I have noticed this year many luxuriant plants of Rnmex pulustrls, a well- known but somewhat rarely-occurring meuiber of the London flora. Near the same place I also found single individuals of Bromiis arvensis and Gallmoga parrAJlora. The occurrence of the last plant is important, although it was very far from obvious how its seed had been brought there. If it once gets a firm footing north of the Thames it must, judg- ing from its abundance in the neighbourhood of Kew, become one of the commonest London weeds. Between the Adelaide Eoad and Belsize Park I have seen this season Bromus secalinus, CUenopod'uim olidum, and Lathyrus Aphaca. This last plant has also occurred this year on the site of the Exhibition, South Kensington, where Medicago falcata and Centanrea amara have also turned up for the first time. According to Dr. Boswell- Syme, all the Centanrea Jacea he has seen from the neighbourhood of London belongs to the form amara. The Exhibition ground has pro- duced abundance of other forms of this plant, but I have not met with amara before. — W. T. Thiselton Dyer.
R. plical/is, W. and N., occurs at Bishop's Wood, Ilampstead, and is among the most interesting discoveries of Professor Areschoug, of Lund,