Anatomy &c. of the Colies. 251 
In the Humming-birds, then, the flexor longus halluces, by 
means of a broad sheet of delicate tendinous strands, joins 
the anterior, flevror perforans, tendon at the level where it 
branches (text-fig. 25). This sheet undoubtedly represents 
all that remains of four separate and independent branches. 
The fibres of this sheet, which are attached to the tendon to 
D. I1., are furthermore, it is to be noted, rather more strongly 
developed than those running to the other branches. Nowin 
Macropteryx (one of the Swifts) the plantar tendons appear 
to differ markedly from those of all other Cypselidze in that 
2), 
25). 
Diagrammatic figures of the plantar tendons of Colius (22 
( 
Macropteryx (23), Cypselus (24), and a Humming-bird 
I, IL., IIL., [1V.=Tendons to digits I-IV. 
Fl.p. =F lexor perforans. 
F1.h.= Flexor longus hallucis. 
the flecor longus hallucis runs, as a separate tendon, directly 
into that branch of the flexor perforans which runs to D.IV.; 
it sends off, however, above the point where the three tendons 
of the f. perforans diverge, a branch to the hallux. A refer- 
ence to the accompanying diagrams (text-figs. 22-25) will 
shew that if this branch to the hallux were connected by 
