Page:Popular Science Monthly Volume 12.djvu/377

Rh logical interest, and very surprising results may be obtained by a careful study of all the conditions, and an ingenious complication of the experiments.

Thus it is quite easy to have half a dozen or more persons engaged in performing parts of an experiment, each one being ignorant of what the other has done. The mind-reader then ravels out the thread by beginning at the end and working backward, or vice versa. The rapidity with which the experiments may be performed is remarkable, sometimes occupying less time than is required to arrange them.

The chief points, then, for the beginner to observe are:

 1. Impress upon your "subject" the necessity of fixing his mind on the object and its locality. 2. Concentrate your attention on every movement of the subject. 3. Never hazard a guess.

Hoping that these few directions will enable others interested in this entertaining and scientific trick to repeat the experiments successfully, and referring the reader to my previous letter for an explanation of the performances without physical contact, I am, yours, very truly.

To the Editor of the Popular Science Monthly.

In corroboration of Mr. Gillman's statements regarding the change of color or "chameleonization" of the Florida lizard (the species of which I presume to be Anolis principalis), and which is noticed in the December number of permit me to say that, in 1871, while in North Carolina, I had a number of these lizards in captivity for the purpose of studying and observing their habits, and in 1873 published in the Rod and Gun a short paper as the results of my observations, which fully confirm those made by Mr. Gillman, as the following extract will show: ". . . The first peculiarity noticed about them was their change of color; before retiring for the night a sheet of paper was thrown over the box, and removed the next morning. To my amazement my pets, that had been a vivid green color the day before, were now of a dirty-brown tint, and extremely sluggish in their movements; but, to my great delight, so soon as the rays of the sun fell upon them, the green returned, and they became as lively as ever. This change of color is very curious and peculiar, taking place under a variety of circumstances. For instance, after burrowing in the sods (with which their box was lined) on their return to the light they would at first be brown, but recovered their normal tints shortly afterward. When asleep the green color would frequently be replaced by brown, and, still more curious, if during the day the sun for any length of time was obscured by clouds, the same effect was produced. The manner in which the green tint replaced the brown was very interesting. In some instances a little patch of green would appear on the end of the snout, others would appear in different portions of the body; these would extend and gradually coalesce until the whole body had resumed its usual tint." During the procreative act, there was an ever-varying change of color from the most vivid green to dull, dusky brown. During anger, and while feeding, these changes were very noticeable. I have never seen the colors change so rapidly as Mr. Gillman states, but this may be due to the fact that his observations were made upon individuals free and unrestrained of their personal liberty, mine upon captives.



HE University of Cambridge, with much éclat, recently conferred the degree of LL.D. upon Mr. Charles Darwin. This circumstance has elicited much diversity of comment on the part of the press. Some maintain that the conferring of this honor is to be construed as a virtual indorsement of the doctrines that are associated with the name of this eminent naturalist; and they regard the action of the university as a triumph of the advanced biological school over the clerical and conservative party by which the university has been hitherto dominated. Others maintain that the proceeding is susceptible of no such interpretation, but that the degree was awarded simply in recognition of the important services of