492 
Fall. 
iutimato]y as to appopj perfectly in- 
corporated. The iris is exceedingly 
contractile — as all may have observed 
Avho have watched a bird dying. Birds 
do not expire with eyes open, as is the 
case with man and the lower {mimals, and 
when they are expiring, you may readi- 
ly observe the great power they pos- 
sess of dilating and contracting the 
pupil. The muscles, as in man, ai-e 
six in number — four straight and two 
oblique. In many birds the eye-ball 
possesses very httle mobility, and in 
some of the owls it is so closely fitted 
into the orbit as to be immovable. 
Plow the eye adapts itself to near and 
distant objects is one of the most ab- 
struse questions in physiology. Three 
explanations have been oifered. 1. By 
bringing forward the crystalfine lens 
[Nov., 
neai'er to the cornea, without altering 
the form of the whole eye or the crys- 
talline itself. 2. By changing the figure 
of the globe of the eye, so as to increase 
the distance between the cornea and 
retina, as you pull out the joints of a 
common spy-glass ; and 3. Without 
altering the general form of the eye, 
by increasing the sphericity of the 
crystalUne, and thus increasing its re- 
fractive power. The first Avas the 
opinion of Haller and the earlier 
physiologists. The second was adopted 
by Blumenbach and many able men. 
The third Avas the opinion of LcAven- 
hoek, Descartes, and Dr. Yoimg, and 
is, perhaps, the true explanation. Sir 
Everard Home and Mr. Hamsden per- 
formed many experiments to elucidate 
the question, but they proved nothing. 
FALL. 
I HEARD a tree to its sole self complain. 
Amid Avhose boughs of rust and scarlet stain 
The solemn sunshine poured its golden rain. 
Strange as the mournful sounds that steal through sleep. 
As if a mist should strive in doAvs to weep. 
The loAV, sad cadence past my sense did creep. 
“ Ah ! little, tender, dancing leaves, that fii'st 
Out of my sere and wintry branches burst. 
With mildest shoAvers and April sunshine nurst ; 
“ IMore A'erdant garlands, fresh Avith life and dime. 
Wherein the light Avinds played a fairy tune. 
And set them glittering to the quiet moon ; 
“ Then in their prime, the thick, gi’ccn, summer leaves. 
Lost in Avhose rustling depth the cricket grieves, 
Or the quaint spider radiant tracery Aveaves ; 
“ SAvift ye forsake, sIoav fluttering to the ground. 
These desolate boughs, no more Avith glory crowned, 
Where every rain may breathe its sighing sound. 
“ One, and another, and another yet. 
No time for grief to ripen to regret, 
Full on my broAv stands the sharp coronet. 
“ Did the co.ld terror, curdling at my heart. 
Strike sudden death, and force your clasp apart, * 
I too Avere all too chill to feel ye part. 
“ But Avarm and fierce the vital torrent floAvs, 
As keener thorns smTound the brightest I'ose, 
Death’s bitterest draught life’s ardor only knows.” 
