'60 1 he Scottish Naturalist. 



for the names and other particulars concerning the plants known 

 to them. But it needs only a little experience of the untrust- 

 worthiness of this method in actual work to prove its insufficiency. 

 Without the actual specimens it will be found impossible to obtain 

 the certainty desirable in ascertaining the species described by any 

 author, or to determine the identity or difference of the species 

 and varieties of one country with those of another. 



It can hardly be matter of surprise, however, that in some cases 

 the herbarium is undervalued when we see the condition of the 

 specimens contained in it. From their scrappiness, as well as 

 from the want of care in their preparation, an inspection of some 

 herbaria is a positive pain instead of the pleasure it ought to be, 

 and that a fair amount of care in the selection of specimens and 

 in their preparation would insure it should be. 



A good local herbarium, such as should be prepared by, or 

 available to the members of the Natural History Societies and field 

 clubs, now so numerously scattered over the length and breadth of 

 the land, ought to show the plants of the district to which it 

 relates. There should be a full and extensive series of each of 

 them, to illustrate its life-history from the first appearance of the 

 seedling till its full development. 



Of each species of plant there ought to be a well-chosen series 

 of specimens to illustrate the changes it undergoes when growing 

 amid different surroundings, such as in open and in shady spots, in 

 dry and in damp places, with sufficient space for full development, 

 or crushed in among other plants. In fact the influence of the 

 physical environment shows itself in so many ways that it is useless 

 to attempt to sum them up here : but the effects are well deserving 

 of regard in the formation of a herbarium, and will be found far 

 more extensive and important than is generally supposed. Then 

 in the case of herbaria to illustrate the flora of some district of 

 considerable extent — e.g., of Perthshire — it is very desirable to show 

 the distribution, both superficial and altitudinal, and also the 

 varieties, if such occur in the subdistricts. To fulfil these aims 

 requires good series beyond what might be needed for the 

 herbarium of a small area. 



There are comparatively few plants that do not show consider- 

 able differences in the appearance of the leaves if traced with care 

 through life ; yet few herbaria show a good series of the changes 

 undergone. Even so important organs as the cotyledons are 

 seldom to be seen in herbaria, though much *may be learned from 

 them ; inasmuch as they, like embryonal structures in animals, 



