212 MR. A. W. HILL—REVISION OF 
In Peru there is much untravelled country and plants have been collected from 
spots more or less isolated. Around Lima, Pickering, of the United States Exploring 
Expedition, in 1840, collected some four or five new species, and some of these have 
never been sent home since. Considerable additions to our knowledge of this region 
were also made by Maclean, a merchant of Lima, and by Matthews. Of recent 
travellers, Weberbauer * has brought many new species to light, from the Andes near 
Oroya, from the province of Sandia on the borders of Peru and Bolivia, and from the 
department of Ancachs in Northern Peru. From this latter district he has collected 
some interesting forms which show affinity to the species of Ecuador. 
On my own journey around Lake Titicaca and thence to Cuzco five new species of 
Nototriche were found. A few species collected by Copeland, though from the summit 
of the Puno railway, are all different from those which I hastily gathered in the same 
region—a fact which points to the great number of species of this genus which may be 
found in a small area. Fiebrig and also Steinmann have recently made journeys into 
S.W. Bolivia, and brought a few new species to our notice. The collection made by the 
latter has been described by Solms-Laubach t. 
CONCLUDING REMARKS. 
The diversity in the leaf-form, in the distribution and character of the tomentum, &c., 
exhibited by the species of the genus Nototriche make it difficult to believe that they 
represent in their varied forms an expression of adaptation to particular conditions of 
environment. Should it be held, however, that a given specific type appears to be more 
partieularly adapted to its situation than another, it then becomes a matter of difficulty 
to explain the occurrence of several different species in close association on the same 
substratum 1. 
Another remarkable point in connection with the distribution of this genus is the 
extraordinarily local character of some of the species, to which allusion has already been 
made, since a single species may be confined to one particular and isolated area, where 
it exists as it were on an island cut off from its nearest allies. 
From a consideration of these facts the conclusion is arrived at that the numerous 
specific forms partake of the nature of chance variations, sports, or mutations $. 
Such mutations may have arisen in considerable numbers and have either persisted 
in their place of origin as a small local species showing fairly close resemblance to other 
forms, or they may have spread further afield into the domains of a species of a widely 
different type. As such mutants spread ever further from their point of origin they 
may in their turn have given rise to new and slightly differing races, and so have 
* Weberbauer, in Engl. Bot. Jahrb. xxxvii. pp. 580—587. 
t Solms-Laubach, in Bot. Zeit. 1907, pp. 119—138, taf, 2. 
t E.g. N. sericea, N. pedatiloba, N. argyllioides, N. Orbignyana, and N. pedicularifolia were all collected at 
Vincocaya, and were growing in voleanic ash at about 14,600 ft. alt, The first three species were collected by 
myself within a few yards of each other, while the train stopped at Vincocaya station. 
§ Cf. Solms-Laubach, in Bot. Zeit. 1907, pp. 130-131. 
