254- Retrospective Criticism. 



apt to perish if kept for a short time too moist ; and, if allowed to get too dry, 

 the young fibrous roots will share the same fate, more particularly if the pots 

 are exposed to the direct rays of the sun." (F/. Cah., vol. ii. p. 9.) 



TropcB' olum hiberosum, introduced in 1834, but only lately figured by Maund 

 and Paxton, is the most ornamental species of the genus. It may be considered 

 about as hardy as the common potato ; and what particularly deserves atten- 

 tion in future experiment is, that its tubers are eatable, and agreeably 

 flavoured. 



Mr. Lambert was the first, we believe, who grew these tubers in England, 

 and presented them at table; and Mr. Cameron has lately written an excellent 

 paper on their culture, which will be found in No. xiv. of the Floral Cabinet. 

 Mr. Cameron planted sbout a dozen tubers in April, before they began to 

 vegetate, and he raised other plants from cuttings, and kept them under glass 

 till thej' were nearly a foot high, and turned them out in July. Both modes 

 succeeded equally well, and the twent3'-five plants, when taken up in Novem- 

 ber, were found to have produced half a bushel of tubers. The sets were 

 planted 3 ft. apart, and the stems were so luxuriant, that they covered a space 

 of at least 6 ft. in circumference. In the Epsom Nursery, some plants which 

 were turned out were staked, like peas, in consequence of which each formed 

 a dense mass of verdure, 4 ft. high, and full 6 ft. in diameter. {Paxt. Mag. of 

 Bot., vol. v. p. 50.) When boiled, the tubers are of a soft pulpy substance, 

 and, Mr. Cameron says, " in taste resembling sea-kale, mixed with the hot' 

 taste of garden cress." The council of the Caledonian Horticultural Society, 

 as the reader will find by turning to p. 106., consider the tubers to be of very 

 delicate flavour, resembling the richest asparagus." Mr. Young of Epsom 

 found the tubers, " when boiled, superior in flavour to any potato, though 

 disposed to be watery, and not boiling firm." We would strongly reconimend 

 the culture of this plant, for the purpose of ascertaining whether anything can 

 be made of it as an esculent vegf table. — Cond. 



To prepare Gooseberry Cuttings luhicli shall not throw up Suckers. — Instead 

 of rubbing off the buds in the usual manner, cut them out with a shield of 

 solid wood : one third of the cuttings so prepared will perish, but those that 

 live will never throw up suckers ; the adventitious buds which produce them 

 being removed. " The reason of so many of the cuttings perishing is, that 

 cuttings made by the ordinary process send out roots from the remains of 

 every eye under ground, as soon as the growing season commences ; whereas, 

 by the method now recommended, every vestige of the bud is removed, and 

 the roots issue from every part of the stem, but are sent forth at a much later 

 period of the season ; and, consequently, the buds drop off before the cuttings 

 are furnished with roots for their support. The usual depth to plant the 

 cuttings is from 4 in. to 6 in." {Ibid., vol. ii. p. 26.) 



Propagating Boses by Cuttings of the Roots. — Take long, fleshy, thick roots, 

 and cut them into lengths of from 2 in. to 3 in. each ; in the latter end of 

 February, lay the cuttings flat, about 4 in. apart, in a bed of very rich soil. 

 Cover them with 1 in. of light soil, 1 in. of good rotten cow-dung, and 2 in. of 

 common soil. " Each root will send up one or more strong shoots, producing 

 abundance of fine healthy fibrous roots among the dung. They should be 

 transplanted singly in winter, and will flower freely the ensuing season. Most 

 of the hardy roses may be obtained in the same way, but it is most applicable 

 to the moss rose and rose unique." (ilf?-. Cameron in Fl. Cab., vol. ii. p. 25.) 



Art. II. Retrospective Criticism. 



Mr. Niven's Experiments on Vegetable Physiology, (p. 161.) — Rejoicing to 

 see Mr. Niven engaged in the physiological experiments detailed in the April 

 Number of this Magazine, I am only complying with his request in offering 

 him a few observations and suggestions connected with his enquiries. 



I. As regards the flow of the crude sap. It has been already established. 



