THE society's NOTE-BOOKS. 115 



fronds from frost has interested me, and prompts the further sugges- 

 tion that those so large and numerous on many tropical ferns may 

 possibly, to them, serve as a screen from heat, and tend to check 

 evaporation of moisture from the frond when the air is dry, and 

 possibly also to retain such moisture from dew or otherwise as might 

 from time to time come to refresh the plant. 



As to the appearance and development of hairs, scales, etc., 

 upon plants generally, it seems clear that in certain natural orders 

 certain forms are observed to be prevalent on many or most of the 

 plants belonging to them ; that in some species they are generally 

 more numerous and conspicuous than upon other species of the 

 same natural order; but when we come to the individual plants 

 themselves, there is in their hairs as much diversity of development 

 as there is in the hirsute adornment of the male of that noble 

 animal who subordinates all other created things to his own use 

 and pleasure, his female counterpart forming only occasionally a 

 rare exception to prove the rule. 



That this animal developes differently under differing atmo- 

 spheric conditions may be seen by comparing a pretty-faced 

 specimen from a manufacturing town with a ruddy clodhopper 

 reared in the agricultural districts. The difference, however, 

 might not be so evident if the specimens were prepared for 

 examination by being soaked in potash for a week, squeezed flat 

 in a hydraulic press, and fixed in balsam between two slabs of 

 plate-glass. W. Teasdale. 



Fern-Scales.— These occur more or less abundantly on all the 

 British ferns that I have examined. They vary very considerably 

 in general form as well as in shape and size of the cells. They 

 should be looked for, not on the back of the frond (except in 

 Ceterach), but on the stipe, the lower portion of which is usually 

 completely covered with them. Many of them polarise well. 



W. H. Beeby. 



Plant-Hairs.— Those interested in plant-hairs should get a 

 specimen of our native (?) plant, Alyssiim calycinum. Almost all 

 parts of the plant are covered with hairs of a very peculiar shape. 

 I give a rough sketch of one of these hairs on Plate III., Fig. 8. 

 Some examples are much simpler than this, while others are very 

 much more irregular. They polarise beautifully. W, H. Beeby. 



Medicago.— Is Medicago ever found with quadrifid leaves ? I 

 have found four-leaved Oxalis, but never four-leaved Medicago. 

 The answer to this question might throw some light on which is 

 the true shamrock. W. H. Beeby. 



Acidium compositarium.— These cluster-cups should be viewed 



