VERNAL FLOWERS. 279* 



between causes and effects ; and especially to look through 

 second causes, to the Great Being who is the First Cause of 

 all ; " himself, uncaused." 



But to return to the question, " what causes Spring ?" or to 

 state it in another form, by what means does the Almighty 

 produce the changes which this season presents ? To answer 

 this, we must refer to astronomical geography, which, pointing 

 out the course of the sun, shows us that having journeyed to 

 his utmost southern boundary, he returns, crosses the equator, 

 and with rapid strides advances towards the northern hemis- 

 phere, beaming more directly upon us, and increasing the tem- 

 perature of the atmosphere ; to chemistry we owe our know- 

 ledge of the effects of caloric on bodies ; physiological botany 

 shows us the sap or vegetable blood expanding by the influence 

 of caloric, and every exhaling and inhaling organ of the plant 

 commencing operations under the same powerful influence. 

 The earth, released from the icy bonds of frost, turns kindly 

 to the mute, but living children of its bosom, and imparts the 

 maternal nourishment, which, rushing through every fibre of 

 the vegetable being, invigorates it with health and strength. 



From the first appearance of vegetation in the spring, until 

 the commencement of winter, nature presents an ever varying 

 scene. The phenomenon of the flowering of plants,* is in 

 many respects, similar to that of the putting forth of leaves ;f 

 in both, the same causes either hasten or retard this period. 

 The putting forth of leaves, and the blossoming of flowers, 

 differ however in one circumstance ; the leaves begin by the 

 upper leaf buds ; the flowers by the lower flower buds ; stipes, 

 panicles, and thyrses begin to blossom gradually from the base 

 to the summit. Cymes and umbels blossom from the outside to 

 the centre. 



In plants of the north, transported to the south, the period 

 of the putting forth of leaves and blossoming is hastened ; in 

 those of the south, carried to the north, it is retarded. Even 

 in their native soil, this period varies in some degree in differ- 

 ent seasons. With greater warmth of temperature, we have 

 an earlier appearance of vegetation ; yet in general, this vari- 

 ation is so slight, that botanists are able by observation, to fix 

 with a sufficient degree of accuracy, the time of the flowering 

 of plants in particular latitudes and climates. 



The progress of vegetation varying little from Latitude 40 

 to 43 north, the remarks that we make on this subject, may 



* This is called florescentia. . t Foliation. 



Changes in vegetation Putting forth of leaves and blossoming of flowers 

 agree in some respects, differ in others Plants of the north transported to the 

 south, and the reverse Remarks on the progress of vegetation ; to what extent 

 of country applying. 



