34 ALLEN 
roid coat arose from this plexus. The first volume of Cuvier 
and Valenciennes’ great work on fishes (11) issued in 1828, con- 
tains a short general description of the circulation of Perca, with 
2 excellent plates, which show practically all the vessels, in- 
cluding the afferent and efferent pseudobranchial arteries, and 
10 years later, Jones (41) carefully described and figured the 
retia mirabilia of the eye. 
About this time marked the beginning of the classical writings 
of Hyrtl, Miller, Vogt, and Stannius. Between the years 1838 
and 1872, Hyrtl published at least 7 different papers on the cir- 
culation of fishes, but unfortunately I have had access to only a 
few of them. Miller (50) tells us that in the first one (30) the 
author made a microscopical examination of the gill-filaments, 
and showed that they contained no lymphatic vessels, as had 
been claimed by some previous investigators. He also explained 
correctly the course of the blood from the hyoidean artery to the 
pseudobranchiz, and from thence to the eye. With Hecht, he 
noticed the pseudobranchial artery coming from the circulus 
cephalicus. In 1852, Hyrtl (32) described with considerable 
detail the arterial system of Lefzsosteus, and 6 years later the 
arterial system of the roaches (34). One of the best general 
works on the circulation of fishes is to be found in part IV of 
Miiller’s famous work on Myxinoiden (50), consisting of 130 
pages and 5 plates. He takes up almost the entire circulatory 
system of cyclostomes, selachians, and several teleosts in a com- 
parative way, going into great detail over the blood supply of 
the pseudobranchiz, choroid gland, and air-bladder. Vogt’s 
splendid monograph on the Anatomy and Embryology of the 
Salmon was published in 1845, but unfortunately I could get 
access only to the plates, of which several were devoted to the 
adult, and many others to the development of the circulatory 
system in the embryo. In Stannius’ Handbuch der Anatomie 
der Wirbelthiere (74), there is a brief, but perhaps the best, gen- 
eral description of the circulation in the several groups of fishes ; 
there are, however, no plates. The author does not go into 
quite as much detail regarding the blood supply of the pseudo- 
branchia, eye, and air-bladder as Miiller, but goes into more 
detail concerning the larger trunks and the vascular supply for 
the visceral organs. 
