
f 
1891.] Notes on the Hearts of Certain Mammals. 861 
NOTES ON THE HEARTS OF CERTAIN MAMMALS. 
BY IDA H. HYDE. 
FA preparing a thesis forthe degree of bachelor of science at 
Cornell University, in the spring of 1891, certain facts were 
observed and conclusions reached which have been thought 
worthy of presentation, if only as an evidence that further investi- 
gation is needed. 
Professor Wilder placed at my disposal the following materials : 
Many hearts of the sheep and domestic cat, several human hearts, 
and the hearts of a monkey, panther, raccoon, hyena, dog, deer, 
calf, horse, donkey, and rabbit. 
Special attention was given to the following parts: The 
Tuberculum Loweri, Eustachian valve, Thebesian valve, coro- 
nary sinus, and the oblique vein of Marshall, a few of the 
facts that seem of chief importance I shall state in the briefest 
possible manner. 
The Tuberculum Lowert—According to “ Wilder and Gage's 
Anatomical Technology,” “the distinct presence of the Tuberculum 
Loweri and the Eustachian valve have as yet not been determined 
in the cat.” Nevertheless, I found what I consider the homolo- 
gue of the Tuberculum Loweri of the human heart present in 
every heart examined. Although Hyrtl denies its presence in 
the human heart, all other authorities agree that it is a constant 
feature of it. 
The Eustachian Valve-—Of the hearts examined, the Eustachian 
valve was found only in man, monkey, and a remnant of it in the 
cat, but not extending above (cephalad) the coronary sinus 
orifice as in man and monkey, but below it (caudad) and protects it. 
In the foetus of the cat it is of relatively as great in extent as in 
man, but in the adult cat only a valve guarding the coronary sinus 
orifice remains, It is this valve that has been mistaken for the 
Thebesian valve by several anatomists. 
The Thebesian Valve—The statements conce ing the Vieussens 
and Thebesian valves are perplexing. Allen and Gegenbaur say 


