142 J. J. TVILLIS — EXPERIMENTAL GEASS PLOTS AT ROTHAMSTED. 



The struggle for existence "u-hich is going on between plant and 

 plant may be illustrated by a comparison of the pcr-centages of a 

 few grasses on the unmanured and the most highly manured plots. 



Unmanured. 



Alopecurus pratensis 0-52 per cent. 



Anthoxcmthum odoraticm. . . . 5-20 ,, ,, 

 Avena flavescens 3-49 ,, ,, 



,, puhescens 3-55 ,, ,, 



JBriza media 6-40 ,, ,, 



Cynosurus cristatus 1-11 ,, ,, 



Dactylis glomerata 0-90 ,, ,, 



Festuca ovina 21-67 ,, ,, 



,, pratensis 0-13 ,, ,, 



Poa pratensis 0-09 ,, ,, 



The complete Flora of the experimental plots may be summarised 

 as follows : — 



Total number of species 93 



,, ,, genera 67 



,, ,, orders 23 



Number of species of Acotyledons 15 



,, ,, Monocotyledons .... 24 



„ ,, Dicotyledons 54 



Amongst these are several species not commonly met with on 

 meadow land, — such, for instance, as Rammcuhis auricomtis, Vicia 

 Cracca, Vicia sepium, Galium Aparine, Sonchus oleraceus, FritiJ- 

 laria meleagris, Trifolitim procumhens, and Ornithogalum umheUatum. 

 But these are only represented by a few individuals, and form no 

 appreciable proportion of the crop. Amongst the acotyledons are 

 included eleven species of Fungi found on the various plots. One 

 fern, Ophioglossxim vulgatum, and three species of mosses, Sypnum 

 squarrosum, H. rutaluliim, and S. Mans, are also met with. 



In the many points of interest brought out in these investiga- 

 tions it is found that even plants of the same genera differ' so 

 materially in their character and habit of growth, that, when in 

 association with each other and with other plants, and subject to 

 a great variety of conditions as to manure, they compoi't themselves 

 in the struggle very differently. In order to gain further informa- 

 tion respecting this subject, samples of the soil from all the experi- 

 mental plots have been taken, to a depth of five feet, and the roots 

 have been separated and carefully noted upon. 



In conclusion, it may be mentioned that Messrs. Lawcs and 

 Gilbert have now in preparation a full report on the results of these 

 experiments, in which the whole subject will be most exhaustively 

 treated. 



