PART IV. 
LECTURE XXXVIII. 
THE FLOWERING SEASON OF PLANTS, 
Vernal and Summer Flowers. 
On entering the fourth division of our course, we find before us an 
open field, freed in a great measure from the technicalities of sci- 
ence, and presenting a smooth and delightful path. Hitherto, we 
have been clearing our way through difficulties, and overcoming ob- 
stacles; first, we were obliged to learn to analyze plants according 
to the strict rules of botanical science ; next to examine the organs 
of plants, anatomically and physiologically ; we then investigated 
the principles of classification, as exhibited both in the natural and 
artificial methods, and followed the arrangements of plants as pre- 
sented in these different methods. 
The language of Botany is now familiar to the diligent student, 
who can enjoy the pleasant reflection, that by his own industry and 
application, he has elevated his mind to that state, in which it may, 
with little further effort, enjoy the pleasant views of the vegetable 
kingdom which now present themselves. Thus, the traveller, hav- 
ing toiled to gain some acclivity, looks complacently around, enjoy- 
ing the beautiful view before him in proportion to the efforts made to 
attain it. 
We will now suppose the dreary season of winter yielding to the 
gentle influences of spring, and organized nature awakening to new 
life and beauty ; — for animals, no less than plants, seem vivified and 
quickened by the returning warmth of this delightful season. How 
many w^andering through life, " with brute, unconscious gaze," have 
never made the inquiry, " 'what causes Spring?" With the greater 
part of mankind the ordinary phenomena of nature excite no inter- 
est ; it is only when something unexpected occurs, that they think, 
either of first or second causes. But it should be the main object of 
education to teach youth to reflect, to seek the connexion between 
cause and effect 5 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 V 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 re- 
fer to astronomical geography^ which, pointing out the course of the 
sun, shows us, that having journeyed to his utmost southern boun- 
dary, he returns, crosses the equator, and with rapid strides ad- 
vances towards the northern hemisphere, beaming more directly 
upon us, and increasing the temperature of the atmosphere ; to che- 
mistry we owe our knowledge 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 powerml influ- 
ence. The earth, released from the icy bonds of frost, turns kindly 
to the mute, but living children of her bosom, and imparts the ma- 
ternal nourishment, which, rushing through every fibre of the ve- 
getable being, invigorates it with health and strength. 
Remarks introductory to the fourth part — What causes spring? 
