CLIMATE. XIX 



of that Flora remark that the great characteristic of British climate, 

 when compared with other European countries in the same latitude, is 

 the comparatively small range of temperature between wmter and sum- 

 mer. In the south-west of the kingdom this distinguishing feature must 

 be most marked, and probably our climate acts most upon our flora 

 through this equability of the temperature and the general humidity of 

 the atmosphere. " Yet it is difficult even to present impossibility to trace 

 out very special connections between plants and climate. In its relations 

 to plants climate involves most varied combinations of temperature and 

 humidity, of exposure to sun and wind, shade and shelter. If time and 

 place be both taken into account, by the season, and the character of the 

 locality, and other circumstances, the combinations become endless in 

 their variety and proportions." {Watson, Cyh. Brit. vol. iv. 145.) Al- 

 though our climate is so humid, yet our ramfall, as Dr. jNIerrifield says, 

 is not a large one. With reference to this subject he makes the following 

 important statements : " The humidity of a district should be judged 

 more by the number of ramy days than by the quantity of rain which 

 falls, because fine rain falling for several successive days, not amounting 

 to so much as a single heavy shower, will render the climate more moist 

 than another where the rain falls heavily and then stops. Many days in 

 the year the sky is completely overcast, and it is but seldom our atmos- 

 phere is free from cloud." (pp. 8, 9.) The effects of our climate are 

 shown in the abundance of the Ferns, the profusion of Cotyledon 

 umbilicus, and other moisture-loving species. Although the winters are 

 generally remarkable for their mildness, yet at intervals one will brmg 

 with it severe or protracted cold, and its effects will be clearly seen the 

 succeeding spring in the gardens of Plymouth and its neighbourhood, 

 since the ordinary immunity from such weather leads the owners to 

 introduce into them many comparatively tender species, the cultivation of 

 which in the open air would not be attempted in most parts of England. 

 Frosty nights are very frequent in the sprmg, and occasionally the cold is 

 of sufficient severity so late in the season as to injure the young foliage 

 of the oak, and partially destroy the unfolding fronds of the ferns. 



" Our hottest months are June, July, and August, when the averages 

 are 59-92°, 63-07°, and 62-40° Fahrenheit, thus showing July to have 

 the advantage. Our coldest months are January, averaging 42-34°, 

 February, 43-86°, and December, 42-35°, the former on the whole being 

 colder than either December or February. Like every other place we 

 have some extreme readings, but these m Plymouth, as in all the south- 

 west districts, are comparatively rare. The maximum temperature in the 

 shade which I have recorded is 93° Fahrenheit, on June 27th, 1866. The 

 minimum is 14° Fahrenheit, on December 27th, 1869. The maximum 

 should be received with caution, because I am afraid heat must either 

 have been reflected or radiated from surrounding substances. I have 



