306 NOTES ON THE BOTANY OF KXPERTMINTAL GRASS-PLOTS. 



in 1872 we liad the cxporicnco gained in former rears to aid us in 

 starting, and the amount of undetermined was in the majority of 

 cases less than one per cent. Tlie only really indeterminable parts 

 are the portions of grass culms that are quite destitute of leaves and 

 Howers. Hence great care is necessary after the sample is dry not to 

 break the stems to pieces. Generally speaking, the smallest scrap of 

 a leaf may be identitied, as well as the glumes and the prain of the 

 grasses. Of seetls or fruits belonging to any of the other orders very few 

 enter into the samples. The achencs of the Itanuncidi, seeds of Ceras- 

 tium, mericarps of Conopodium and Anthriscus, achenes of Tragopogon, 

 Taraxacum, and Humex, and the seeds of Zuzula are all easily referred 

 to their proper places, as well as the leaves and stems of all the 

 plants except the grasses. The characters of the leaves of the grasses 

 are various, and are found in tlieir texture, surface, colour, point, 

 ligule, mode of curling or folding together when dry, nature of the 

 margin, colour and relative prominence of the midrib, ttc. By one or 

 more of these characters it is possible to distinguish pieces not more 

 than a quarter of an inch long — in fact, almost any piece with two 

 ends. With regard to the influence of the manures on the botanical 

 characters, or any of the characters I have indicated, it appears to be 

 very slight throughout tlie whole series of experiments. Jt is mainly 

 limited to the vigour, and consequent size of the plant, and the degree 

 of hairiness. That is to say, it is possible to divide the species 

 represented on the plots into those with constantly hairy and those 

 with constantly hairless leaves. The hairs may be exceedingly 

 minute, and only visible in a certain position, as on the upper surface 

 of the folded leaves of Foa pratensis, or more or less prominent on 

 both surfaces, as on the hard leaves oi Arena pubescens, and on the 

 soft leaves of Uolcus lanatm— the " Hard Hairy " and " Soft Hairy " 

 of the boys. Avenajlavcscens, Bromus, and Ant/io.ra)itkui)i present dif- 

 ferent kinds of hairs, difhcult to describe but facile to distinguish. 

 Thus it becomes intelligible that, beginning with tlie less complex 

 samples, and knowing what species grow on the plots whence they 

 were taken, it is not so formidable a task as one might suppose. But 

 it is tedious in the extreme when a handful of small stuff will keep 

 one busy for a day or two. 



The object of this brief sketch of the experiments on permanent 

 grass-land at Bothamsted is not so much to make them more widely 

 known as to offer sufficient information to botanists as to render the 

 experiments themselves moie intelligible and interesting to those who 

 are obliged to be content with paying an occasional flying visit. Any- 

 one desirous of obtaining more exact details of the plan and extent of 

 the experiments will find what they want in the papers and reports 

 referred to above, and Mr. LaAves has in preparation a full report of 

 the results of these experiments, in which the whole subject will be 

 as exliaustively treated as available data will permit. 



