ing has acquired the morphological and 

 physiological characters which distin- 

 guish it." Development is "the process 

 of differentiation by which the primitive- 

 ly similar parts of a living body become 

 more and more unlike one another." Both 

 definitions are Huxley's. 



The evolution of organic matter now 

 claims attention in detail. Of the origin 

 of first life, we know absolutely nothing. 

 The doctrine of Evolution does not deal 

 with that. There are, however, many hy- 

 potheses upon the subject. Lord Kelvin, 

 the eminent physicist, has suggested that 

 unicellular life may have been transferred 

 to this globe from a wrecked planet. This 

 hypothesis obviously aids us very little, 

 for it merely transfers the original scene 

 of action to some other world. Personal- 

 ly, I prefer the idea that the first proto- 

 plasm was produced by the action of the 

 sun upon inorganic matter not unlike the 

 colloids, and that it ''fed upon the pre- 

 vious steps in its own evolution." In this 

 connection, I may say that two points are 

 certain — viz., that vegetable life preceded 

 animal life, and that the first forms of life 

 were mere specks of jelly, without or- 

 gans. Can these primitive specks be 

 created at the present time ? Or, in other 

 words, can protoplasm be manufactured 

 by artificial processes ? The answer must 

 be No; not by any process now known, 

 although a great number of experiments 

 have been made with the object of manu- 

 facturing unicellular vegetable life. Dur- 

 ing the years between 1870 and 1880, this 

 question was thoroughly thrashed out, 

 and at first the balance seemed to be very 

 evenly held between the supporters and 

 the opponents of spontaneous generation. 

 The investigations of the late Professor 

 Tyndall, however, conclusively proved 

 that biogenesis, that is, all life from pre- 

 vious life, is the condition at the present 

 day. But I must add Huxley's words of 

 warning, viz., "that with organic chemis- 

 try, molecular physics, and physiology 

 yet in their infancy, and every day making- 

 prodigious strides, it would be the height 

 of presumption for any man to say that 

 the conditions under which matter as- 

 sumes the qualities called vital, may not 

 some day be artificially brought togeth- 

 er." And further, "that as a matter not 

 of proof but of probability, if it were 



given me to look beyond the abyss of 

 geologically recorded time, to the still 

 more remote period when the earth was 

 passing through chemical and physical 

 conditions which it can never see again, 

 I should expect to be a witness of the 

 evolution of living protoplasm from non- 

 living matter." 



The first protoplasm must be extreme- 

 ly ancient, for the remains of sea-weeds 

 are found in the oldest strata, and vege- 

 tation implies the manufacture of proto- 

 plasm from inorganic matter. 



When the earth w r as in the condition to 

 which Huxley referred, the constantly 

 decreasing heat, and the recurrence of 

 the seasons produced, by slow r degree ;, 

 changes in the congenital character of the 

 forms of life. Every individual varied 

 somewhat from its predecessors, and 

 those forms which possessed variations 

 most suitable to the environment were 

 the ones which eventually survived. The 

 transition from the protophyta, the lowest 

 class of vegetable life, to the protozoa, 

 the lowest class of animal life, must have 

 been a very simple matter in the condition 

 in which the earth then was. Indeed, to- 

 day the difference between the lowest mi- 

 croscopic animals and the lowest micro- 

 scopic plants is by no means clearly de- 

 fined. 



Innumerable hosts of life made their 

 appearance upon our planet while the 

 surface was going through the cooling 

 process, and they were, at first, of course, 

 of the most primitive kind. But the same 

 laws were always at work, viz., no two 

 living things were exactly alike when 

 they made their appearance upon this 

 earth, although the differences between 

 several forms might be very slight. Varia- 

 tion was, and is, the order of the day. 



The individuals which possessed varia- 

 tions in accordance with the environment 

 persisted, while those having injurious 

 variations had a tendency to disappear. 

 Congenital variations were (and are) 

 transmitted with great certainty. This is 

 Mr. Darwin's "Process of Natural Se- 

 lection," called by Mr. Spencer"The Sur- 

 vival of the Fittest." 



The other Darwinian factor in evolu- 

 tion is Sexual Selection. It is that depart- 

 ment of Natural Selection in which sex is 

 especially concerned. Anything which 



20s 



