SCIENTIFIC SUMMAEY. 621 
(c.) The nerves of muscle never penetrate the sarcolemma, as supposed by 
Kiihne and others. 
(d.) There are no such structures as unipolar nerve-cells ; all ganglion-cells 
are bi-polar, i.e., have two nerve-filaments proceeding from them. 
(e.) These filaments are coiled, one round the other, and proceed on leaving 
the cell in opposite directions. 
(f.) The so-called dark-bordered nerve-fibres divide into the finer filaments. 
Relation of Starchy Matter in Liver to Food. — This subject was fully dis- 
cussed in a memoir written by Dr. Robert McDonnel, a well-known Irish 
physiologist, and read before the French Academy on the 8th of May last. 
The writer pointed out, among other peculiarities of the hepatic organ, that 
the quantity of amylaceous matter which it contains bears little proportion 
to the weight of the liver as compared with that of the body. ’ The volume 
of the fiver of the cat in a state of health, and fed on flesh, is nearly double 
that of the fiver of the dog during the most active period of the digestive 
process ; nevertheless, the fiver of a large cat which had been weU fed pos- 
sessed only about two-thirds of the starchy matter produced by the fiver of a 
dog which had been fed on carrots and bread. Hence, it may be concluded 
that the saccharine forms of food give origin to the amylaceous matter much 
more easily than nitrogenous food. It is true, however, that the fiver can 
prepare the amylaceous substance from the fibrine of the bk)od, the gluten of 
corn, and also from fresh-meat. “ Contrary,” says the writer, “to the opinion 
of an eminent physiologist, I am assured that there is no more starchy matter 
in the fiver of animals fed on gelatine than there is in that of those which 
have been starved. It is evident, therefore, that the fiver cannot convert 
gelatine into starch, and the same thing may be said of fat.” 
What are Renal Diseases ? — This question may fairly be asked, since the 
recent inquiries of M. Rombaud tend to show that what have always been 
regarded as morbid conditions of the kidney are in reality not so. This savant 
has drawn the following conclusions as to the nature of three forms of what 
are still termed renal diseases : — 
(1.) Calculus, diabetes, and albuminuria are not diseases of the kidney. 
(2.) The anatomical alterations which are found during post-mortem 
examinations of patients who have died of any of these afi“ections are the 
consequence rather than the cause of the disease. 
(3.) The etiology of these three diseases may be expressed in four words — ^ 
alteration of the blood. 
(4.) This alteration consists in the excessive production of uric acid, which,, 
according to the conditions under which it is present, may act either on the 
glucose or the albumen of the circulating fluid, producing, sometimes gravel 
or gout, sometimes diabetes, and occasionally albuminuria. 
The Result of Engrafting Animal Tissues. — A remarkable memoir, detailing 
the results of some curious experiments regarding the vitality of engTafted 
animal tissues, has been written by Signor Mantegazza. He has engrafted 
the organs of one animal upon the body of another Avith the most surprising 
consequences. Some of the tissues thus engrafted underwent fatty degenera- 
tion ; but others appeared to five as well in the new as in the old organism, 
being united in course of time to the new one by blood-vessels and connective 
tissue. Ill the frog the engrafted reproductive gland continued to produce 
