INTRODUCTION. 



place between April and August, and a loss of weight from September to 

 March, the loss of weight corresponding with a greater excretion of car- 

 bonic acid, from the destruction of fat in the winter months. While this 

 work was passing through the press, some observations made by the Rev. 

 M. Hansen, of Copenhagen, have been published which show that three 

 distinct seasons of growth in stature, increase in weight, and of equipose, i 

 occur in children ; the season of growth being from April to August, of 

 increase in weight from August to December, and these two kinds of/ 

 activity are followed by a period of rest extending from December to 

 April. Mr. Hansen also found that a continued increase of temperature 

 at any time of the year favoured an increase in the weight of the body. 



Climate. 



For determining the climate of a country, a district, or a health resort, 

 no method is so interesting and satisfactory, and at the same time so 

 easily carried out, as recording the condition of vegetation at different 

 seasons of the year. Meteorological observations made by means of in- 

 struments require an amount of skill, time, and perseverance which many 

 persons do not possess, and at best such observations are open to many 

 sources of error from the liability of the instruments to get out of order, 

 and from other causes ; and they are, to the majority of persons, singu- 

 larly wanting in passing interest. The interpretation, moreover, of such 

 observations is often difficult and unsatisfactory, as differences of climate 

 are due to subtle combinations of sunshine, rain, wind, and soil, which no 

 instruments can record nor figures represent, and which are only truly 

 declared by the varying conditions of vegetation, and remotely, by the 

 insects which feed, on it, and by birds and animals which feed on both 

 and are themselves influenced by such conditions. 



A familiar acquaintance with many of the winter health resorts of 

 Europe, and a traveller's acquaintance with many other countries and 

 climates, has impressed me with the superiority of the biological over the 

 physical methods of distinguishing climates ; and its advantages are fully 

 recognized by the public, as is evident from the frequent correspondence 

 in the press relative to the early or late blossoming of plants, the times of 

 the appearance of insects, and of migratory birds, in different parts of the 

 country. On the other hand^ writers on climatology do not sufficiently 

 recognize its importance,' but trust too implicitly to mere averages of 



' This remark does not apply to Dr. H. Bennet, the author of "Winter and Spring 

 in the Mediterranean." Writing to me on this subject Dr. Bennet says : " I am glad 

 to find that you agree with me in attributing special value to botanical phenomena in 

 appreciating meteorological conditions and cUmate. In my Mediterranean travels I 

 found it an infallible guide. An hour's observation gave the key." 



