In order to avoid a return to this phase of the question, another use of the vicinists should at once be pointed out. It is the possibility of increasing the yield of the new variety. If space admits of sowing the seeds of the vicinists, a quarter of the progeny may be expected to come true to the new type, and if they were partly pollinated by the dwarfs, even a larger number would do so. Hence it should be made a rule to sow these seeds also, at least when those of the true representatives of the novelty do not give seed enough for a rapid multiplication. Other dwarfs are recorded to have sprung from species in the same sudden and unexpected manner, as for instance _Ageratum coeruleum_ of the same nursery, further _Clematis Viticella nana_ and _Acer campestre nanum_. _Prunus Mahaleb nana_ was discovered in 1828 in one [614] specimen near Orleans by Mme. LeBrun in a large culture of Mahaleb. _Lonicera tatarica nana_ appeared in 1825 at Fontenay-aux Roses. A tall variety of the strawberry is called "Giant of Zuidwijk" and originated at Boskoop in Holland in the nursery of Mr. van de Water, in a lot of seedlings of the ordinary strawberry. It was very large, but produced few runners, and was propagated with much difficulty, for after six years only 15 plants were available. It proved to be a late variety with abundant large fruit, and was sold at a high price. For a long time it was prominent in cultures in Holland only. Varieties without prickles are known to have originated all of a sudden in sundry cases. _Gleditschia sinensis_, introduced in 1774 from China, gave two seedlings without spines in the year 1823, in the nursery of Caumzet. It is curious in being one of the rare instances where a simultaneous mutation in two specimens is acknowledged, because as a rule, such records comply with the prevailing, though inexact, belief that horticultural mutations always appear in single individuals. From Korshinsky's survey of varieties with cut leaves or laciniate forms the following cases may be quoted. In the year 1830 a nurseryman named Jacques had sown a large lot of elms, [615] _Ulmus pedunculata_. One of the seedlings had cut leaves. He multiplied it by grafting and gave it to the trade under the name of _U. pedunculata urticaefolia_. It has since been lost.