Page:The Journal of Indian Botany.djvu/83

 Pulicaria rajputanae Blatter and Uallberg sp. nov., I.e. p. 535, allied nearly to P. crispa Benth, but differing in the following points : the plant is woolly- all over, the margin of the leaves is not recurved, the ligules are much longer than the bracts, the pappus is six times as long as the achenes. Dist. Jodhpur and Jaisalmer. Flowering and fruiting in October and November.

Glossocardia setosa Blatter and Hallberg sp. nov., I.e. p. 536, distinguished from G. linearifolia Cass, by the following characters : the plant is much larger and generally erect, the shape of the outer bracts is different, the awns of the achene spread almost horizontally and are setose,' sometimes half way up, at other times along their whole length. Dist. Jodhpur and Jaisalmer. Fruiting in October and November.

Convolvulus densiflorus Blatter and Hallberg sp. nov., I.e. p. 545 (near C. rkyniospermum Hochst), Dist. Jodhpur and Jaisalmer. Flowering and fruiting in October and November.

Convolvulus gracilis Blatter and Hallberg sp. nov., I.e. p. 545. Dist. Jodhpur. Flowering and fruiting in November.

C. T.

Guppy, H. B., Plant-Distribution from the Stand-point of an Idealist. Jour. Linn. Soc. XLIV No. 299 {July 1919) pp. 439-472.

It would probably not be a mis-statement to say that in regard to the origin of species and to evolution in general, the vast majority of Botanists as well as Zoologists are divided into two camps, the Darwinians who believe in progressive evolution by small changes, and the Mutationists who contend that specific differences are often, or perhaps always, caused by sudden changes ; and to this camp belong also those who pin their faith on the trans- mission and acquirement of characters on Mendelian lines. But as far as the writer of this notice is aware in neither camp would it be denied that generic differences have in the past arisen out of smaller (specific) beginnings, and have in turn led to the larger differences which separate the orders or fami- lies as we know them to-day. Mr. Guppy in the paper under notice contends that the present distribution of the families of plants, the great majority (over 70 per cent.) of which occur in both the Old and the New World, points to an even distribution in some bygone age over the whole globe; an age when conditions were much more uniform than at present and when first the larger groupings then the families were segregated. The splitting up of these families into genera and then into species followed in another era when climatic differentiation had become established. In other words evolution has been not from small differences growing into larger, but by the laying down first of the major lines of cleavage between plant groups, and the sub- sequent splitting up of those groups into smaller ones.

In a series of tables at the close of the paper it is shown that the idea usually held that the junction in the north of the two great land masses of America and Eurasia has afforded opportunity under suitable climatic condi- tions for a mixing of the floras of these two areas, is not borne out by statistical evidence in the case of the families, only partly so in regard to the genera, but much more so with the species. It is also shown that while the majority of families ignore in their distribution the existence of the ocean barriers between these two parts of the land, they are very much affected by