Houston.] 326 (Dec. 7, 
In a former article, ‘‘On the Homologies of the Molar Teeth,’’ etc., I 
traced the modifications of the superior and many of the inferior molars ot 
the ungulate mammals to a parent quadrituberculate type. In a subse- 
quent essay* I traced the origin of the inferior sectorial to a primitive five- 
tubercled, or ‘‘ tubercular sectorial’’ type. Farther than this I did not go, 
and made no attempt to derive the few cases of triangular superior molars 
then known, nor the type of the superior sectorial. The revelations of the 
Puerco fauna show, that the superior molars of both ungulate and unguic- 
ulate mammalia have been derived from a tritubercular type; and that 
the inferior true molars of both have been derived from a “tubercular 
sectorial’’ type. Shall we look for the origin of the latter in a trituber- 
cular tooth also, ¢.¢., tubercular sectorial without heel; and will the 
crowns of the true molars of the primitive mammals alternate with, in- 
stead of oppose each other? This is a probable result of future discovery. 
On the Synchronous-Multiplea Telegraph. By Prof. Houston. 
(Tiead before the American Philosophical Society, December 7, 1883.) 
Prof. Houston said: ‘It is with considerable pleasure, Mr, President 
and gentlemen, that I am here this evening to call your attention to a dis- 
covery in electricity that appears to.me to be of very great practical value 
to the world, The present decade has witnessed such marvelous progress 
in electrical inventions that many of us have perhaps been disposed to be- 
lieve that but little new could reasonably be expected, but, unless I am 
greatly mistaken, the invention which I am about. to describe to you, is 
greater even than that of the telephone. 
“Before proceeding to the details of the invention of the synchronous- 
multiplex telegraph system of Mr. Patrick B. Delany, it will, perhaps, be best 
that your attention should first be called to some of the practical purposes 
for which it is applicable. Briefly stated, the value of this invention is to 
be found in the fact, that by its use the simultaneous transmission of 
numerous telegraphic dispatches over one and the same wire is readily ac- 
complished, Hitherto, the only system that accomplished this, to any con- 
siderable extent, in actual practice, was the quadruplex system, and this, 
as you well know, is not only limited to the simultaneous transmission of 
four dispatches, but these are necessarily sent, two each, in opposite direc- 
tions. You will, therefore, readily understand the great value of Mr. 
Delany’s wonderful invention, when I inform you that not only can the 
number of simultaneously transmitted dispatches be very gr satly increased, 
even indeed as far as seventy-two, but that all of them can be sent in the 
*Journal Academy Natural Sciences, Philadelphia, March, 1875, 
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