As to "measuring by eye," this was a test put to her accidentally. About the beginning of June, 1917, for lack of any better idea at the moment, I determined to teach her the use of the yard measure (the metre), and without having any definite object in view. So I fetched the yard-stick and told her the names and the meaning of the divisions three times; but she seemed unable to work up any enthusiasm for the subject, and I therefore did not attempt to question her. Many duties intervened, and so I forgot the whole matter for several weeks. But on 25 July I thought it might be just as well to test her eye for measure, and this reminded me of the yard-stick. So I asked for fun: "Do you remember that I showed you the yard-stick?" "Yes!" was her prompt reply. In astonishment I continued: "How many centimetres are there to the metre?" "100!" "And how many decimetres to twenty centimetres?" "2." "And how many decimetres in two and a half centimetres?" "25." Now, for the joke of the thing, I determined to test the accuracy of her eye, for I had not yet fetched the yard-stick, and she had, in fact, not seen it for many weeks. So I pointed to the outside edge of a small picture-frame that I--at a guess--took to be about twenty-two centimetres in length. At the same time I must own that I have never exercised my judgment in this line to any very great extent. "How long is this lower edge?" I asked her, "from _here_ to _here_?" (pointing): her answer was, "25." I then tested it by the stick; it was twenty-six! I pointed to a larger frame, putting the same question, she answered "50." I measured, and found it to be 75. Again I showed her a smaller picture, and she rapped "19." Then I showed her a piece of chocolate--"7" was her reply--it was seven and a half. Later on, when she was in the mood she became able to guess within _half_ a centimetre at a distance of about thirty centimetres and at greater distances--up to one metre; I estimated the difference to vary from about one to ten centimetres. Of late I have not given her much practice of this kind, for from the beginning she has not cared much for it. But I have made the experiment of seeing whether she can distinguish colours in the same way we do. To make this test I daubed some of the most important colours on a sheet of paper, writing the name beneath each, and the next day I daubed the same colours on another piece of paper--but in different sequence, and without adding their names. The ready response to my questions gave further proof as Lola's good memory as well as of her perfect ability to differentiate.