Volume 4

Descriptive and illustrated catalogue of the physiological series of comparative anatomy contained in the Museum of the Royal College of Surgeons in London / [By R. Owen].

  • Royal College of Surgeons of England. Museum.
Date:
1833-40
Catalogue details

Licence: Public Domain Mark

Credit: Descriptive and illustrated catalogue of the physiological series of comparative anatomy contained in the Museum of the Royal College of Surgeons in London / [By R. Owen]. Source: Wellcome Collection.

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    actions ; and besides, they are influenced by external circumstances, such as heat and cold ; for both vegetables and animals have their degrees of heat, which is conducive to health; and many different classes in both, vary very considerably in this respect, and as this circumstance is varying upon this globe, called seasons, most vegetables and most animals have their seasons of propagation*. “ Air or the atmosphere is another external influence which is neces- sary, but more in the vegetable than in the animal. Air is necessary for the first principle of action, viz. life; and it is necessary for health. Light is absolutely necessary for most vegetables, but not so much for many anirnalsf. When all these necessary circumstances meet in each, generally they are fit for propagation. “ From what has been observed, it must appear that propagation is one of the completest operations of either an animal or vegetable. However, in vegetables it would appear that a strong state of health rather hinders the powers of the male and female ; but we are to consider that what is termed a strong state of health in a vegetable is great growth; which might be reckoned one of the species of propagation. Animals have their limited growth; therefore that which was spent upon themselves while growing, may now be employed in propagation. But nature was not willing that either all vegetables or all animals should propagate. * The ideas in the preceding paragraph are more clearly expressed by Hunter, in his Observations on the VesicultB seminales, (Animal CEconomy, Ed. 2nd, p. 36.), in the following words : “ Animals have their natural feelings (for procreation) raised or increased according to the perfection of the parts connected with such feelings; and the disposition for action is also in proportion to the state of the parts and the excitement of such feelings. But that these feelings may be duly excited, it is necessary that the animal and the parts should be healthy, in good condition, and in a certain degree of warmth suitable to that class to which the animal belongs. In the greatest part of the globe there is a differ- ence in the warmth of the same district at different periods, constituting the seasons; and the cold in some of them is so considerable as to prevent those feelings or dispositions in animals from taking place, and to render them, for the time, unfit for the purposes of generation. This is owing to the testicles becoming at this season small, and being therefore unfit to give such dispositions, as is the case in very young animals. This fact is very obvious in birds.” t [Many Entozoa, e. g. live, grow and propagate in the dark recesses of animal bodies ; where nei- ther light nor air can penetrate.] B 2