Bauhaus-Universität Weimar

Titel:
The Cyclopaedia of Anatomy and Physiology, vol. 2: Dia-Ins
Person:
Todd, Robert Bentley
PURL:
https://digitalesammlungen.uni-weimar.de/viewer/image/lit25760/467/
GENERATION. 
3. lid somewhat like the cork of a phial, be¬ 
tween which and the main body of the case a 
spiral spring is interposed, so contrived that 
when the case is immersed in water the spring 
expands, forces off' the top of the case, and 
allows the seminal fluid to issue from the 
interior. 
We must refer to the anatomical articles for 
an account of the varieties of structure of the 
male generative organs in different animals. 
In some of those in which the vesiculæ sémi¬ 
nales are wanting, as in the familiar example 
of the dog, copulation is necessarily longer 
than in others. Very little is known as to 
the uses of the prostatic body or Cowper’s 
glands. See Generation, Organs of. 
Spermatic animalcules.—The most remark¬ 
able circumstance undoubtedly which is known 
respecting the spermatic fluid, is the almost 
constant existence in it of an immense number 
of minute moving bodies of the nature of In¬ 
fusorial animalculæ,— the well-known and 
celebrated spermatic animalcules, which, since 
the time of their first discovery in 1(177, have 
excited the curiosity and speculative fancy of 
many naturalists.* 
The spermatic animalcules have been found, 
at one time or other, in the semen of almost all 
the animals in which they have been sought 
for,f but at that period of their life, and in that 
season of the year only, when the animals to 
which they belong are fit for propagation. 
They are diminished in number, or even en¬ 
tirely disappear, after very frequent emission 
of the seminal fluid. They almost always 
exist in the fluid secreted by the testicles, and 
verv often in that of the seminal vesicles, into 
which they have doubtless been introduced 
along with the fluid of the testicles. 
From these circumstances, as well as others 
to which we shall afterwards advert, there is 
good reason to believe, that the existence of 
seminal animalcules in the male product is in 
some way or other intimately connected with 
the integrity of its fecundating property ; if not, 
* Haller states as his conviction, that Ludwig 
Hamm (then a student at Leyden) was the first 
discoverer of the seminal animalcules in August of 
1677. Leeuwenhoek claimed the merit of bavin«- 
made the discovery, in November of the same 
year, and in 16/8, Hartscelcer published an account 
of them, professing to have seen them as early as 
in 1674. A great deal has since been written re¬ 
garding them. Needham, Buffon, Der Gleichen, 
Spallanzani, Prévost and Duma«, and Wagner, 
may be mentioned as those who have devoted 
most attention to these curious little animals. Our 
remarks are taken chiefly from the investigations 
of the three last authors, as well as from original 
observations. ° 
t The class of fishes are stated by Messrs. Pré¬ 
vost and Dumas to form an exception to this 
remark, these observers not having been able to 
discover any seminal animalcules in the seminal 
fluid of fishes ; but they are stated to have been 
seen by older authors (see Haller’s Elementa, vo). 
vii. p. 521); and from the latest investigations it 
appears that they exist, though of a form different 
from the spermatic animalculæ of most other ani¬ 
mals. The author has seen them very clearly in 
the seminal fluid of the Perch, and one or two 
other fishés. See Fig. 51, p. 112, vol. ii. 
459 
as some are inclined to hold, the essential cause 
of it. 
The form, appearance, and size of the semi¬ 
nal animalcule are different in almost every 
different animal, and in each species of the 
more perfect animals the kind of animalcule 
seems, like that of Entozoa, to be constant and 
determinate. While, therefore, these little crea¬ 
tures, by their minute size and their general 
structure and appearance (so far as these are 
known), are distinctly animals of the infusorial 
kind, their residence in other living animals 
entitles them to be classed among the Entozoa. 
Baer considers them as most nearly allied to 
the Cercaria among the Infusoria, and gives 
them the very appropriate name of Sperma¬ 
tozoa. 
In what we have hitherto said of the seminal 
animalcules, we have drawn our description 
principally from what has been observed in 
quadrupeds and birds, but they differ consi¬ 
derably from these in some of the inferior 
animals. Czermak* holds that these various 
forms may be referred to three principal heads, 
viz. :— 
1. Cephaloidea, merely rounded bodies with¬ 
out tails, existing in fishes and some Annelida. 
2. Uroidea, thread-like, ' in Mollusca, Am¬ 
phibia, and some birds. 
3. Cephal-uroidea, consisting of a globular 
and a tail part, in Mammalia, Birds, and In¬ 
sects. 
The first of these kinds of Spermatozoa are 
like the Monades among Infusoria, the second 
resemble the Vibriones, and the third, as has 
been already remarked, the Cercaria. 
It is important to remark that, in so far as 
has as yet been ascertained, the form and size 
of the spermatic animalcules do not bear any 
intimate relation to the animal in which they 
exist, nor to the ova of the female. In respect 
of form, Messrs. Prévost and Dumas state that 
the head is usually of a round lenticular shape 
in quadrupeds, while in most birds it is of a 
long oval shape ; but in some birds the form is 
the same as in most quadrupeds. The semi¬ 
nal animalcules present nearly the same ap¬ 
pearance in man and in the dog. Various 
markings are represented in the cephalic por¬ 
tion of the animalculæ of some quadrupeds by 
Messrs. Prévost and Dumas, but these, we 
are inclined to believe, are not constant, and 
are appearances which have arisen from acci¬ 
dental circumstances. 
In respect to size, there appears to be still 
a greater want of correspondence. The semi¬ 
nal animalculæ are said not to be larger in the 
whale than in the mouse. They are very much 
larger in Insects, Mollusca, and others of the 
lower animals than in Man. In the snail they 
are fifty-four times longer than in the dog, and 
considerably larger in the mouse than in the 
horse 
The following table exhibits approximative^ 
the sizes of the spermatic animalculæ of some 
wlen^SS86 ” der Lehre V°n dei’ SPermatoz°en, 
2 h 2
        

Nutzerhinweis

Sehr geehrte Benutzer,

aufgrund der aktuellen Entwicklungen in der Webtechnologie, die im Goobi viewer verwendet wird, unterstützt die Software den von Ihnen verwendeten Browser nicht mehr.

Bitte benutzen Sie einen der folgenden Browser, um diese Seite korrekt darstellen zu können.

Vielen Dank für Ihr Verständnis.