50 



Buchanan 



as the simpler one. Records of the first response to excitation of each 

 nerve in turn in the two preparations are reproduced in figs. 7 and 11 

 respectively. The muscle used for recording in Exp. 40 was again one 

 of those in which the direct effect to excitation of the motor part of the 

 nerve was double ; the same-limb reflex time was longer in the last two 

 responses than in the others, and the whole crossed-reflex time also became 

 longer in the third and fourth responses, so that the extra reflex time at 

 first remained unchanged ; it finally in the last response became shorter. 

 Exp. 55 will be referred to again (p. 53). 



In all the other experiments the extra reflex delay was shorter through- 

 out than the same-side reflex time in the same preparation, although it 

 was as a rule no shorter than this time frequently is. In three of these 

 [Nos. 18, 45, and 47] the action of the drug was incipient. In Exp. 18 the 



Fk;. 7. — Electrical responses of the gastrocnemius of a frog which had been 

 injected the day before with 1 minim 0'04 per cent, liquor strychniae. The 

 jireparation was abnormally excitable, but the limbs were no longer at all 

 stitt'(Exp. 40). 



A, first response obtained when the intact sciatic nerve of the same side was excited. The 

 direct effect was double. [Time lines 745 per second.] B, first response obtained wlien 

 the sciatic nerve of tlie opposite side was excited. [Time lines 745 per second.] 



same-side reflex delay was exceptionally long ; the effects were weak, and 

 resembled one another in both kinds of reflexes. In Exp. 45 the crossed- 

 reflex effect was throughout weak, and at first a good deal weaker than the 

 same-side reflex effect ; but as this became weaker each time it was recorded, 

 they were in the end not unlike one another in strength. Fig. 8 allows of 

 the comparison of the two kinds of reflex responses at the beginning and the 

 end of the experiment. In Exp. 47 the crossed-reflex effect was very weak 

 the first time it was recorded, but became in subsequent responses of nearly 

 the same strength as the same-side reflex eftect ; it varied, however, some- 

 what in strength as well as in duration in the different responses. Records 

 of the third same-side and of the fifth crossed-reflex responses are repro- 

 duced in fig. 9. This was the only preparation, besides No. 33, referred 

 to on p. 33, which gave an extra reflex delay decidedly shorter than the 

 same-side reflex time, as we have now learnt to know it, in strychnine 

 preparations. To begin with, it was about llo", but became in the fifth and 



