THE VICTORIAN NATURALIST. 123 



suspend vegetation altogether, shorten the period of growth and 

 hasten that of maturation, and sometimes give rise to the excep- 

 tional phenomena of the second leafing and blossoming of 

 plants and trees in the same year.' The order of the seasons 

 differs with the relative length of the day and night. Growth in 

 length or bulk of vegetables takes place in the dark, while 

 maturation of structures and juices takes place in the light. 

 Hence the plants of alpine regions are dwarfed by the short, cold 

 nights, and hastily matured. In the tropics, where the days and 

 nights are of nearly equal length and the temperature is always 

 favourable, growth is almost continuous (hence an excess of 

 leaves over flowers), and is interrupted only by a lack of 

 moisture. 



The season of maturation is most distinctly displayed by the 

 ripening of fruits and seeds ; but it equally applies to the 

 ripening of the buds, roots and tubers of perennial trees and 

 plants which cast their leaves or die down. 



The season of rest is less marked than in Europe, our indi- 

 genous vegetation being evergreen; our principal trees, being the 

 eucalypts and the acacias, cast their bark annually ; but this does 

 not take place, like the falling leaf in England, at one given 

 period of the year. 



The threefold divisions of the seasons is distinguished among 

 insects by the three stages of their life-history — the perfect insect, 

 the caterpillar, and the chrysalis. Some insects in the perfect 

 form are said to hibernate through the winter, but this is 

 probably only a condition of the survival of a few individuals 

 under favourable conditions. Among birds we find the threefold 

 seasons by the nesting, maturation, by fattening of both young 

 and parent birds, and rest by migration. 



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 tirne so easily carried out, as recording the condition of 

 vegetation at different seasons of the year. Meteorological ob- 

 servations, made by means of instruments, 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, singularly 

 wanting in passing interest. The interpretation, moreover, of 

 such observations is often difficult and unsatisfactory, as differ- 

 ences of climate are due to subde combinations of sunshine, rain, 

 wind, and soil, which no instrument can record nor figures repre- 

 sent, and which are only truly declared by the varying conditions 

 of vegetation, and remotely by the insects which feed on it, and 



