loo INTERNAL SECRETIONS 



gradually in the male ; in young males of about 15 to 25 gr. 

 the experiment was unsuccessful, as in females, whereas in 

 males of 35 to 40 gr. the clasp reflex, although evoked, was 

 weaker than in males of 50 to 60 gr. 



Similar experiments were performed by Steinach and 

 Langhans (Steinach, 1910). They made incisions just below 

 the medulla oblongata or between the cerebellum and the 

 medulla oblongata, and evoked the clasp reflex in some cases 

 for as long as two days. Like Schrader, they take the view 

 that inhibitory centres are to be found, not only in the corpora 

 bigemina, but also in the cerebellum and in the medulla 

 oblongata. Busquet, on the contrary, holds that inhibitory 

 centres are locahsed in the cerebellum only; the clasp reflex 

 cannot be evoked after removal of the lobi olfactorii or of the 

 corpora bigemina. When he destroyed the cerebellum only, 

 which consists in the frog of a small transverse border above the 

 medulla oblongata, the reflex could be evoked. The same 

 result was obtained when the middle part of the cerebellum 

 was destroyed with the point of a pin. 



Besides the inhibitory centres there must be a centre for the 

 clasp reflex in the spinal cord ; it is the cervical part by which 

 the muscles of the fore legs are innervated. By destro3dng 

 the spinal cord 2 to 3 mm. below the medulla oblongata, Busquet 

 caused the reflex to disappear. But the reflex persists when 

 incisions are made just below the medulla oblongata and between 

 the third and fourth cervical vertebrae. It is possible that 

 the clasp reflex is caused not only by the weakening or absence 

 of the inhibition from the upper parts, but also by an increased 

 irritability of the spinal cord during heat; the question is 

 worth further investigation as to whether the irritability of 

 the spinal cord may be altered by the internal secretion of the 

 testicle. 



The results obtained in experiments on toads and frogs by 

 Baglioni are contrary to those of the earlier investigators. 

 He confirmed the statement of Albertoni and Tarchanoff, 

 however, that the clasp reflex in the frog can be inhibited by 

 mechanical stimulation of the corpora bigemina. But, on the 

 other hand, Baghoni stated that the clasp reflex is not in- 

 hibited when the corpora bigemina are stimulated electrically, 

 since under these conditions the reflex became even stronger. 

 Another observation of Baghoni corroborates this; by placing 



