9S 



SCIENCE-GOSSIP. 



[May 1, I860. 



By observing the thermometrical changes which 

 occur during the successive hours of each day in any 

 given locality, the curves of daily temperature for that 

 place are constructed, which curves will, of course, 

 differ according to the season. Then by taking the 

 mean temperature of each day of the year, the curve 

 of annual temperature is formed, and it is with this 

 that the observer of seasonal phenomena has chiefly to 

 do. Nevertheless, the influence of temperature upon 

 living organisms is strikingly illustrated in the effects 

 of the daily curve. Eor instance, the opening and 

 closing of flowers, which mostly depends on tempera- 

 ture, is in many cases so regular and precise, that it 

 becomes possible to tell the hour of the day or night 

 with considerable accuracy by this means alone. 

 The operations connected with the annual curve are, 

 of course, much more complex, yet every child is 

 aware of the general effects of summer's heat and 

 winter's cold upon both the vegetable and the animal 

 kingdom. Temperature, however, is not an isolated 

 agency; other meteorological influences, more or 

 less obvious, are associated with it ; and it is the 

 study of these agencies in their relations to the 

 periodic changes visible in organic nature, which 

 constitutes the investigation of seasonal phenomena. 



Eor many reasons, the extensive range of the 

 subjects involved being among the most cogent, we 

 must look to the individual efforts of numerous 

 observers for the successful prosecution of this 

 interesting branch of study. In clays so busy as ours 

 a division of labour is absolutely necessary, at least 

 among amateurs. Leaving, therefore, the meteoro- 

 logical influences which combine to bring about the 

 course of the seasons, let us look at a few of our 

 native seasonal phenomena, restricting our observa- 

 tions, at present, to the noteworthy facts of spring- 

 time. 



Every true lover of nature watches with interest 

 the gradual departure of winter, and hails the 

 approach of the vernal months, preparing himself to 

 sing, with the poet Moir, the lines above quoted. 



And here arises a question or two, well worth 

 considering. All winters are not alike. They differ 

 now-a-days, old folks tell us, from those of lang syne ; 

 and our modern winters differ from each other. Do 

 these dili'erences produce corresponding effects upon 

 the vegetable and animal life of the ensuing season ? 

 or is it of no appreciable importance whether 

 the winter be wet or dry, cold or warm ? 



In respect to insects, an able naturalist (the Rev. 

 L. Jenyns) is of opinion that a wet winter must 

 seriously affect those which pass the colder mouths 

 in a torpid state, heavy rains drowning them in their 

 retreats. Severe cold, he considers, would have 

 little or no effect. Now, here is a point to be de- 

 termined by continued and multiplied observations. 

 We have just passed through a winter of a very de- 

 finite character ; there has been abundance of rain, 

 with little or no frost. It remains to be seen what 



effects have been produced. Will there be a sen- 

 sible diminution in the numbers of those kinds of 

 insects which are known to hybernate ? Is a differ- 

 ence observable between those which pass the winter 

 underground, as compared with such as seek a 

 higher level ? Eor example, the caterpillar of the 

 common cabbage butterfly (Pieris brassicce), when 

 hatched late in the summer, spends the winter months 

 in a crevice of some wall or hollow tree, where rain 

 could hardly reach it ; but the larvae of the saw-fly 

 {Nematus ribesii), like many other insects, burrows 

 into the ground, and consequently, would be much 

 more exposed to the influence of a heavy rainfall. 

 If rains can produce any diminution in the insects of 

 a given year, certainly the floods which have laid so 

 many parts of England under water ought to bring 

 about that result at the present time. Hence the 

 need for careful and extended observation, under- 

 taken in different localities, affected in a greater or 

 a less degree by excessive rains. 



On the other hand, the writer cannot help think- 

 ing that a winter of unusual severity will be found 

 destructive to some extent of hybernating animals. 

 With regard to reptiles, it would seem that they be- 

 come torpid when the thermometer sinks below 50°, 

 and their own temperature then falls to freezing 

 point. If reduced below this, life often becomes 

 extinct. Would not similar influences be likely 

 to affect the insect race, whose circulation is so 

 much more energetic than that of the sluggish rep- 

 tilia? 



In respect to those phenomena which may be re- 

 garded as prognostic of an early spring, or as 

 heralding the vernal season, we may be excused if 

 we mention one or two classes of facts which, how- 

 ever interesting in themselves, are not noteworthy in 

 this respect. 



We find, for example, in the botanical department 

 of a late serial, a communication recording the 

 gathering of the dandelion, groundsel, and chichoeed 

 in December ; on which the editor quietly observes 

 that he believes the said plants may be found in 

 flower at most of the seasons of the year. Let it be 

 remembered, therefore, that there are flowers and 

 insects which appear all the year round, and the 

 discovery of which has, consequently, no seasonal 

 value whatever. It is pleasant to find that, though — 



The rose has but a summer's reign, 

 The daisy never dies ; 



but let a distinction be drawn between the star-like 

 shining of the " wee, modest, crimson-tipp'd flower," 

 and the yellow bloom of its associate, the buttercup, 

 — a true plant of spring, opening its petals at the end 

 of April or the beginning of May. 



Let a distinction be also drawn between local and 

 more general phenomena. Sheltered spots encourage 

 early flowering, [while bleak situations produce a 

 corresponding retardation. Considering the back- 



