638 SCIENCE PROGRESS 



has been entirely defeated by modern zoological discovery. It is therefore com* 

 forting to read that Prof. O'Donoghue is not of this opinion, for he says : 



The starting point of all modern zoological work goes back to the publication 

 of Charles Darwin's famous book on The Origin of Species in 1859. It is 

 probably no exaggeration to say that this book had a more profound influence on 

 all branches of thought, and not simply Biology alone, than any other that has 

 appeared since or for some hundreds of years before, and we are proud to think 

 that it was written by a zoologist. Its publication was followed by a storm of 

 discussion, and a great deal of that intellectual friction that tends to generate heat 

 rather than light. This gradually died away, as the main principles it advocated 

 were accepted by all biologists, and then followed a period of activity in research 

 and revolution in ideas such as had not been witnessed since the great revival of 

 learning, at the end of the 15th and beginning of the 16th centuries Whether 

 or not all his interpretations of the causes at work were right does not concern us 

 here so much as the inestimable service he rendered in bringing home the great 

 fact of Evolution, and thereby providing a solid foundation for future endeavour. 

 Zoological and botanical work, previous to this, had resulted in the accumulation 

 of an enormous number of facts and large collections of material, but, as Theseus 

 would have been lost in the Cretan labyrinth without the thread supplied by 

 Ariadne, so would the biologist have been lost in the maze of individual and 

 unrelated observations but for the clue provided by Darwin. 



The Mathematical Amoeba 



In Science of December 13 last, Prof. S. O. Mast gives us an admirable critical 

 article on " Problems, Methods, and Results in Behavior," in which he examines 

 and summarises mechanistic and vitalistic opinions on the behaviour of animals. 

 Consider the following case: In 191 5 I was examining a number of small 

 amoebae taken in a pool of fresh water close to our hotel in Alexandria. These 

 beautiful little creatures each lived like a caddis- worm in a house consisting of 

 minute stony particles, and were moving about with their houses catching small 

 diatoms. Presently one protruded a pseudopodium, caught a diatom by the 

 middle, and tried to ingest it. Now, as every one knows, a diatom is a double 

 cone in shape, that is, is shuttle-shaped; and the length of the diatoms in question 

 was almost as great as the diameter of the amcebse. Hence my poor friend 

 having caught his diatom by the middle could no more swallow it in that position 

 than I could swallow a mat row- bone sideways. What did the amoeba do ? After 

 thinking out the mathematical problem for a time, it proceeded to turn the diatom 

 until the end of the latter entered its mouth-aperture and was sucked in. But it 

 was still unfortunate, for when nearly half the diatom was drawn in the amoeba 

 could not stretch its " mouth '' sufficiently to take in the whole width of the diatom 

 in its middle section. It remained thinking for some time with the diatom half in 

 and half out of its mouth, and then wisely gave up the problem, suddenly ejected 

 its intended prey, and went off in an opposite direction to look for another and 

 a smaller victim. First, did the amoeba show any evidence of a mathematical 

 knowledge of the shape of a double cone ; and, secondly, if amoebae are attracted 

 only by chemiotaxis, why did not the same amoeba return over and over again to 

 the same diatom ? In both cases it looks as if amoebae possess experience, that is, 

 memory of the shapes of diatoms, as well as judgment, that is, the power of 

 refusing to persist in futile endeavour ! Will mere chemiotaxis explain what I 

 saw? {Vide my hypothesis of the Ego Cell in Science Progress, July 1916.) 



Prof. Mast laughs at the "anecdotage" of those who tell stories about the 

 intelligence of animals, but repeats Menault's tale of the drake which dragged * 



