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Rudolf Magnus  (1873-1927)

A German physiologist, he became professor at Utrecht University, The Neatherlands, in 1908 and later founded the Institute of Pharmacology there.

He wrote Goethe als Naturforscher (Goethe as a Scientist), which has been translated into English.

Around World War I  he began investigating animal posture in collaboration with de Kleijn, van Leeuwen, and G. G. J. Rademacher (variously spelled).  In 1924 he published Körperstellung (Body Posture), the work for which he is most famous.  In 1927 he was nominated for a Nobel prize, but his untimely death prevented any award.

In 1925 he gave the Croonian Lecture “Animal Posture” in England, later published in the Proceedings of the Royal Society of London (series B) 98: 339-353.

In 1926 he gave the Cameron Prize Lecture “Some Results of Studies in the Physiology of Posture” in England, later published in The Lancet 208:531-536,585-588.

Considering their interest to some Alexandrians, I hunted up these old journals at the local medical school library and laboriously typed the lectures into HTML format for this website.

Prof. Magnus demonstrated a number of automatic righting movements in decerabrate preparations (mostly of rabbits and cats) initiated by movement of the head relative to the neck. Apparently something in the remaining nervous system (that is, remaining after decerabration) contributes to this movement, but he doesn’t say it’s in any particular anatomical spot.

In Prof. Magnus’s second lecture you find the oft quoted dictum:  “the head leads and the body follows.”  The full paragraph gives the context:

“The mechanism [of a decerebrate preparation] as a whole acts in such a way that the head leads and the body follows. The attitudes impressed upon the body by a certain head position in the decerebrate preparation closely resemble the natural attitudes shown by the intact animal during ordinary life.”
A decerebrate preparation is an animal that has had its brain cut out or otherwise destroyed. Even today if you utter “I am Prof. Magnus” outdoors in Utrecht you will hear a great swooshing of shrubbery as every cat and rabbit in the vicinity heads for the hills. Well, I made that up. Reading Prof. Magnus may turn you into an anti-vivisectionist.

It should be emphasized that the reflexes Prof. Magnus demonstrated cannot be seen, at least not directly, in the intact animal, that is, an animal deprived of Prof. Magnus’s attentions. For example, though according to Prof. Magnus a brainless cat will reflexively extend its forelegs when you pull its head back, if you take a healthy cat and pull his head back, his forelegs won’t extend in the least, he’ll just get annoyed. The relevance of Prof. Magnus’s work to healthy animals is limited.

A bit on the terminology Prof. Magnus uses.  A preparation is an animal that’s been operated on.  Extirpate and ablate both mean to surgically remove something from the animal. An intact animal is one that’s been left alone. Tonic means long lasting.  Tone refers to muscle tension.  The labyrinth is part of the inner ear.  Afferent nerves carry impulses inwards, sensory nerves in other words;  efferent nerves carry impulses outwards, motor nerves. Proprioceptive means sensed within the body,  exteroceptive means sensed outside the body. Unilateral means on one side only, left or right. Cervical means concerning the neck. The cortex cerebri is these days called the cerebral cortex. Dorsal refers to the back or upper surface of the animal,  ventral the abdominal or lower surface. Caudally means towards the rear. Anterior is the front, posterior the rear.  The brain-stem is the lower part of the brain.  The thalamus is higher up.  A flexor muscle decreases the angle of a joint,  an extensor increases it;  an elevator raises up something. Muscles tend to work in pairs, and the antagonist is the one working against the muscle under consideration. Supine means turned up. The myotatic reflex is the contraction of a muscle responding to a stretching force acting on it.  There are twelve pairs of cranial nerves which go directly to the brain; the eighth pair is the auditory one. Impress your friends by saying bulbus oculi instead of eyeball. The pons, rubro-spinal tract, pyramidal tract, and red nucleus are all part of the central nervous system.  I’m not sure what he means by bulb, perhaps the olfactory bulb, another part of the central nervous system.

Here then are the lectures by Rudolf Magnus:

Animal Posture
Some Results of Studies in the Physiology of Posture