You will think me a horrid bore, but I beg you, IN RELATION TO A NEW POINT FOR OBSERVATION, to imagine as well as you can that you suddenly come across some dreadful object, and act with a sudden little start, a SHUDDER OF HORROR; please do this once or twice, and observe yourself as well as you can, and AFTERWARDS read the rest of this note, which I have consequently pinned down. I find, to my surprise, whenever I act thus my platysma contracts. Does yours? (N.B.--See what a man will do for science; I began this note with a horrid fib, namely, that I want you to attend to a new point. (The point was doubtless described as a new one, to avoid the possibility of Dr. Ogle's attention being directed to the platysma, a muscle which had been the subject of discussion in other letters.)) I will try and get some persons thus to act who are so lucky as not to know that they even possess this muscle, so troublesome for any one making out about expression. Is a shudder akin to the rigor or shivering before fever? If so, perhaps the platysma could be observed in such cases. Paget told me that he had attended much to shivering, and had written in MS. on the subject, and been much perplexed about it. He mentioned that passing a catheter often causes shivering. Perhaps I will write to him about the platysma. He is always most kind in aiding me in all ways, but he is so overworked that it hurts my conscience to trouble him, for I have a conscience, little as you have reason to think so. Help me if you can, and forgive me. Your murderer case has come in splendidly as the acme of prostration from fear. Yours very sincerely, CH. DARWIN. CHARLES DARWIN TO DR. OGLE. Down, April 29 [1871]. My dear Dr. Ogle, I am truly obliged for all the great trouble which you have so kindly taken. I am sure you have no cause to say that you are sorry you can give me no definite information, for you have given me far more than I ever expected to get. The action of the platysma is not very important for me, but I believe that you will fully understand (for I have always fancied that our minds were very similar) the intolerable desire I had not to be utterly baffled. Now I know that it sometimes contracts from fear and from shuddering, but not apparently from a prolonged state of fear such as the insane suffer...