The Catholic bulletin. [volume] (St. Paul, Minn.) 1911-1995, 1915-07-24
CONTINUED from page ID
LIFE AND WORK OF GEORGE
MENDEL.

been discovered that a number of ply
steal characteristics and some physi-
illogical abnormalities are transmitted
from parent to offspring in accordance
with Mendel's principles of heredity,
e. g., the color of the human eye, hair
color, albinism, straight-hairedness and
curliness of hair, congenital prescribe
cataract, night blindness, brachy
lism, alkaptonuria, hereditary epilepsy,
hemophillia, etc. The factor for the
appearance of these and other normal
and abnormal characters may well be
found in the parental gametes, and no
doubt, it follows the Mendelian law.
Nervous disorders that are structural
in character may similarly be inner
tied, and belong to long line of an
cestors. Still, not every congenital
structural disorder is hereditary.
The rigorous application of Mendel-
ian principles of heredity to the total
ity of human nature ignores the Pc
culiar nature of man, and his superior
ity over the animal. The human soul
through it's immateriality transcends
the ordinary conditions that obtain in
the animal generation. life and func-
ton. The human intellect is depend
ent indeed, upon the integrity of the
bodily organization, but it possesses at
the same time, a sphere of function
above the reign of physical laws.
Man is for this reason not victim of
hereditary traits and instincts; his life
history is not written in the parental
gametes, as it is the case with the ami
NAL and plant. His virtues and vices,
his abilities and liabilities are the re-
suit of his own individual effort and
endeavor. 1t is easy to perceive the
materialistic tendency in their new
attempt, unsuccessful as it has been
and will remain, to lower man to the
level of brute creation and to find in
his conduct the play of hereditary
strains and tendencies. Mans trans.
cendant powers of understanding and
free volition constitute him a being
apart from the rest of the living world
White nature dominates and controls
the other forms of life, nurture, educa,
ton, personal initiative, cooperation
with divine grace are the factors upon
which mans conduct and character
are based.
The dominant offspring of the hybrid
are to all appearances entirely SINH
lar in character. Still on further self
fertilization it was found that one
If0T1rAh aTsr
pure, retaining the character in al
subsequent generations with the same
precision as the recessives. The other
two-thirds of the dominants are
mixed: for in the next generation
there will appear from these ances
tors the same numerical ratio of re
cessives, pure and mixed dominants
Mendel was not satisfied to estab
lish these numerical relations amons
the two classes of offspring: bt
sought a reason which makes this re
lation a matter of necessity. 1t was
in his time suspected, if not scienti
fically proven, that the nucleus of thu
germ-cell is the controlling factor il
heredity. Still the study of the germ
cell was not in his time sufficient!
advanced to make possible the exac
understanding of this process. Will
a keenness of perception, which
amounted nearly to intuition, Mende
formulated the doctrine of chrome
J somes, of their behavior during thu
maturation of the gametes of boil
sexes, and then explains the compo
site nature of the fortified germ-ce1l
or zygote. which is constituted of al
} equal number of heritable chrome
somes from both ancestors, both o
which are, therefore, equally poten
, in deciding the character of the off
spring; the determiner for a characte
may come from either one of them.
The zygote formed by the union o
the two gametes bearing opposite
, characters contains chromosomes COZ
: responding to the respective feature
of the parents. At some stage, how
ever, in the formation of the germ
cells there will occur separation o
! the factors which are the agents il
, the appearance of given characte
| =
; characters from each other is know,
, in biology as segregation, and tn
F, determiners which separate in thi
fashion in the subsequent generation
are called allelofnorphic or ALTERNATIVE
, to each other in the constitution of tn
| gamete. Not so much the dominance
of characters as the law of segregation
; Is the prominent feature of Medelial
: doctrine of heredity. The constitution
} of the gametes and zygotes demand
that the process of segregation as
sumo the numerical ratio postulate
5 in Menders Law.
> We presume that gamstes bearin
+ opposite characters are derived from
Z pure strain which always breeds tru,
A cross between the two means tn
4 union of gamete containing cha
: acter, v. g. tallness, with one bearin
a the opposite character, i. e. dwarfnes
S owing to the inhibitory influence {
the former, the hybrid will in appea
/ ance be indistinguishable from pur
r dominant. The difference will appea
e however, in the formation of gamete
b to which the hybrid gives rise !
/ gameto-genesi of the hybrid til
! characters which have remained III
b blended will. segregate from on
+, another, so that half of the gametC
r will contain one, half the other of I'll
1 alternate character. This viii hol