956 SCIENCE. 
meric, or otherwise closely related (some- 
thing chemically very difficult to prove), 
but there can be no doubt that the tectonic 
must bea different and a specific one in 
the chromosomes of every different kind of 
animal. ‘This different construction or ma- 
chinery causes those special differentiations 
in the further development of a fecundated 
egg which characterize a species,* while 
it is the chemically labile nature which 
confers the power of transforming and ap- 
plying energy. 
Moreover, the same author ascribes to 
enzymes the power to form living matter 
from the dead matter of the food. This, 
too, isnotcorrect. The proteolytic enzymes 
merely provide the living animal cell with 
soluble protein (albumoses), but this inac- 
tive protein is converted into living matter 
by the living protoplasm itself (probably 
by the nucleus), but surely not by enzymes. 
Besides the known enzymes that act on 
glucosides, carbohydrates, fats and true 
proteins, there exist certainly still others of 
however a rather narrow sphere of activity. 
Certain mites and a few fungi attack hair 
and horn and utilize therefore keratin as 
food, hence, they must be able to prepare 
an enzyme (keratinase), especially adapted 
to dissolve keratin. Certain fungi easily 
perforate the chitin structures of insects 
and a special enzyme (chitinase) has to be 
assumed also in this case. Still another 
group are the but recently recognized bac- 
teriolytic enzymes, produced by certain kinds 
of bacteria themselves. These enzymes play 
an important réle in the recovery from and 
immunization against infectious diseases. +} 
Their powers of dissolving bacteria, how- 
* The various hypotheses treating this problem 
have been discussed by Ives Delage: La structure du 
protoplasma et les théories sur Vherédité, etc. Paris, 
1895. 
7 Cf. Emmerich and Loew, Bacterolytische Enzyme 
als Ursache der erworbenen Immunitiat und die Hei- 
lung von Infections krankheiten durch dieselben ; 
Zeitschrift fiir Hygiene, Vol. 31, May, 1899. 
[N. S. Vou. X. No. 261- 
ever, are restricted to certain kinds and 
may in many cases act on one kind only. 
It is from the ecological standpoint cer- 
tainly a remarkable fact, that an organism, 
as, e. g., Bacillus pyocganeus produces an 
enzyme which, after reaching a certain con- 
centration, dissolves the bacillus itself! 
The bacillus, so to speak, commits suicide 
by means of its own enzyme—certainly not 
a teleological working of nature for the 
maintenance of species ! 
As to the chemical nature of enzymes three 
questions above all have occupied the mind 
of investigators, viz.: 1. Are the enzymes 
proteins or not? 2. How is the fact to be 
explained that a very small amount of an 
enzyme can transform a relatively very large 
amount of another compound? 3. What 
is the cause of their quite specific action, 
the reason that they can only attack a. 
specific compound and not others, even 
closely related ones? 
The importance of the first question has 
been much overrated and while one author 
asserted they belong to the coagulable 
albumins, another ascribed to them the 
nature of nucleoproteids and still others 
claimed that enzymes are very different from 
any protein matter. It is true, special 
difficulties are encountered in the purifica- 
tion and isolation of enzymes, but it is also 
not less true, in many cases at least, that it 
is quite impossible to separate the enzymic 
activity from protein matter. The tendency 
of certain authors to infer from the nature 
of one enzyme the nature of all the others. 
also, is not justified at all. There may 
exist enzymes in every group of proteins, 
and some may exist that are not proteins, 
although derived therefrom. 
Wurtz* has recognized papayotin, the 
proteolytic enzyme of Carica papaya as an 
albumose and Chittenden} thinks the di- 
* Comptes Rendus, 90, 1379. 
t Transactions of the Conn. Acad. of Sciences, Vol- 
8 (1891). 
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