May 17, 1901.] 
increase in the activity of such solutions. 
Outside of the living cell, therefore, these 
substances do not seem to be able to grow 
or to reproduce. 
Tn this connection it has occurred to the 
writer that the enzymes sustain about the 
same relation to the living cell as do the 
non-nucleated cell fragments. It has been 
proved as the result of numerous observa- 
tions that, if a unicellular organism be 
subdivided by mechanical means, each frag- 
ment thereof will still manifest vital ac- 
tivity. To the biologist, all these frag- 
ments are alive and yet their ultimate fate 
may be very different. Those that are 
nucleated have been found to have the 
power of completely repairing their injuries 
and ultimately develop into complete cells 
again and reproduce by cell-division. On 
the other hand, while the non-nucleated 
fragments frequently retain their vitality 
for days, for example, non-nucleated frag- 
ments of the amceba have been known to 
live for fourteen days, they ultimately per- 
ish. In some cases the non-nucleated frag- 
ments may even heal their wounds and 
engulf food particles ; the latter, however, 
remain undigested and the fragment ulti- 
mately dies without reproduction. In this 
connection Verworn has pointed out that a 
nuclear fragment entirely devoid of cyto- 
plasm can no more regenerate the entire 
cell than can the non-nucleated cytoplasm 
alone. He is, therefore, of the opinion that 
the formative energy of the cell cannot 
derive from either the nucleus or cytoplasm 
alone, but from both. To him the cell it- 
self, and not merely the nucleus, is the vital 
unit, the activities of which are contributed 
to, in part at least, by both the nucleus and 
the cytoplasm ,and that numerous exchanges 
of material actually go on between them is 
supported by the most trustworthy histo- 
logical evidence of the present day. We 
see thus that in the formation of a new cell, 
whether by the natural repair of a cell 
SCIENCE. 
ferments. 
aaa 
fragment or by the usual process of repro- 
duction, both the cell nucleus and the cyto- 
plasm are concerned. It has also been 
shown, however, that both the nucleus and 
the cytoplasm are concerned in the produc- 
tion of the zymogens and ultimately of the 
It would seem, therefore, that 
the enzyme and non-nucleated cell frag- 
ments stand in essentially the same relation 
to the living ‘cell. Both originate in much 
the same manner, both lack the power of 
growth and reproduction, and yet both ex- 
hibit certain vital activities. Would it be 
far from the truth, therefore, to look upon 
the enzyme as the chemical basis of life? 
J. H. Kastie. 
STATE COLLEGE OF KENTUCKY, 
LEXINGTON. 
THE PROGRESS MADE IN ENGINEERING 
DURING THE NINETEENTH 
CENTURY. * 
Tue progress made in engineering during 
the nineteenth century, on the one hand, 
furnishes in itself a reminder of its ultimate 
dependence upon mathematics and the sci- 
ences, and, on the other hand, it attests the 
fact that its great and growing inspiration 
has been the welfare of all the civilized 
world. A hundred years ago but little of 
engineering worth or prominence was in 
existence; so little, comparatively, that a 
glance at contrasting conditions then and 
now ‘will reveal striking differences. 
A century ago traveling in its highest 
development was limited on land to the 
horse and coach, covering perhaps a weari- 
some fifty miles in a day; now a day’s 
travel is eight hundred miles. Then, a trip 
from New York City to Philadelphia con- 
sumed as much time and occasioned more 
fatigue than one from New York to St. 
Louis now; or a journey then from New 
York to St. Louis consumed the greater 
* Read before the Academy of Science of St. Louis 
on February 18, 1901. 
