136 Nature Notes. [Sess. 



One gets a more thorough lesson in physical geography and 

 geology by studying a sand-heap or clay-bank after rain, or 

 the work done by a stream or burn, than by reading many 

 text- books. Text-books should be used chiefly to broaden 

 the knowledge gained through observation. The material 

 for the naturalist to work with is at his door, and " he is 

 a thoroughly good naturalist," says Charles Kingsley, " who 

 knows his own parish thoroughly." Minerals, rocks, plants^ 

 and animals are the necessary materials for field lessons, and 

 the method of study may be expressed in three words — 

 Observation, Comparison, and Inference. By examining and 

 studying a plant, how it grows, how it gets its nourishment, 

 and then observing its relation to the life about it and to the 

 world around, is to acquire knowledge at first-hand. The 

 naming of the parts of a flower and the defining of botanical 

 terms too often passes for botany, but if one is to get any real 

 knowledge of the subject he must go out into the fields. 

 Observation must be aided by experiment and inference. 

 How many have walked through a wood and noticed the 

 common birch -tree covered with what has the appearance 

 of birds' nests, which increase in size until the branches 

 become weighed down with these tufts, or " witches' brooms " 

 as they are commonly called. But how few can tell you 

 what they are or how they have arisen. The tree is attacked 

 by a fungus, which so interferes with the flow of the sap that 

 a host of small interlacing shoots resembling birds' nests 

 is the result. Leaves alone are a source of endless inquiries. 

 How many have observed the various movements of leaves, 

 and noticed the fall of the leaf in autumn, without caring 

 to find out for themselves anything about leaf -motion, or 

 what it is that causes a leaf to fall in the autumn. Questions- 

 like these may make the inquirer desirous of knowing some- 

 thing about the function of leaves and the diseases of our 

 timber- trees. A very prevalent feeling is that the study of 

 practical Natural History is difficult, but there is a sort of 

 freemasonry among field naturalists, and experts are always 

 ready to help in removing difficulties and explaining the 

 puzzles of nature. By coming thus in contact with experts, 

 one gains a practical knowledge which is of more use to him 

 than any amount of book-reading or of work on his own 



