701 



SCIENTIFIC SIDE-LIGHTS 



Transformation 

 Transition 



group the Sauropsida. . . . There is 

 good evidence for the belief that birds have 

 descended from reptilian ancestors. This 

 evidence consists of the remains of fossil 

 birds, some of which show marked reptilian 

 characters, and are toothed. CHAPMAN 

 Bird-Life, ch. 1, p. 1. (A., 1900.) 



3468. TRANSITION FROM BRONZE 

 TO IRON AGE Barbarism Surpassing Civ- 

 ilization. It is especially difficult to de- 

 termine the positive date when any nation 

 made the transition from the Bronze to 

 the Iron Age, and practically impossible to 

 do so in the cases of people who either 

 inhabited countries where iron does not 

 abound, or who never acquired the art of 

 obtaining it. In such event, the substitution 

 of implements of iron necessarily imported 

 from other countries for the native ones of 

 bronze, to which the population had become 

 accustomed by ages of use, was an exceed- 

 ingly slow process, retarded by the mental 

 inertia of the times, and often by national 

 pride in home customs and handiwork. 

 Hence arises the seeming anomaly that 

 among people far advanced in civilization 

 the general use of iron can be recognized 

 only at a comparatively late period in their 

 history ; while among barbarians, incompara- 

 bly below them in intellectual attainments, 

 we find evidence of its employment at im- 

 mensely earlier periods. In Denmark, for 

 example, the Age of Iron corresponds to that 

 of the beech-tree. Hesiod, writing in 850 

 B. C., speaks of the time when " men 

 wrought in brass, when iron did not exist " ; 

 and Homer, altho frequently referring to 

 weapons and implements of bronze, mentions 

 iron but rarely. The Aztecs, at the time 

 of the Conquest, knew nothing of the metal, 

 altho their soil was impregnated with it. 

 The Peruvians, under the same natural con- 

 ditions, were equally ignorant. PARK BEN- 

 JAMIN Intellectual Rise in Electricity, ch. 1, 

 p. 21. (J. W., 1898.) 



3469. TRANSITION FROM NATU- 

 RAL TO SPIRITUAL lAke That from Min- 

 eral to Organic Life. Why a virtuous man 

 should not simply grow better and better 

 until in his own right he enter the kingdom 

 of God is what thousands honestly and seri- 

 ously fail to understand. Now philosophy 

 cannot help us here. Her arguments are, 

 if anything, against us. But science answers 

 to the appeal at once. If it be simply point- 

 ed out that this is the same absurdity as 

 to ask why a stone should not grow more 

 and more living till it enters the organic 

 world, the point is clear in an instant. 

 DRUMMOND Natural Law in the Spiritual 

 World, essay 1, p. 71. (H. Al.) 



34 7 O. TRANSITION FROM TYPE TO 



TYPE Species United by Steady Gradation of 

 Varieties. In the small forest region of 

 Oahu, one of the Sandwich Islands, there 

 have been found about 175 species of land- 



shells represented by 700 or 800 varieties; 

 and we are told by the Rev. J. T. Gulick, 

 who studied them carefully, that " we fre- 

 quently find a genus represented in several 

 successive valleys by allied species, some- 

 times feeding on the same, sometimes on 

 different plants. In every such case the 

 valleys that are nearest to each other fur- 

 nish the most nearly allied forms; and a 

 full set of the varieties of each species pre- 

 sents a minute gradation of forms between 

 the more divergent types found in the more 

 widely separated localities." WALLACE Dar- 

 winism, ch. 3, p. 29. (Hum.) 



3471. TRANSITION, GRADUAL, OF 

 GROUPS AND SPECIES IN GEOLOGIC 

 TIMES If there be any result which has 

 come more clearly out of geological investi- 

 gation than another, it is that the vast series 

 of extinct animals and plants is not divis- 

 ible, as it was once supposed to be, into dis- 

 tinct groups, separated by sharply marked 

 boundaries. There are no great gulfs be- 

 tween epochs and formations no successive 

 periods marked by the appearance of plants, 

 of water animals, and of land animals, en 

 masse. Every year adds to the list of links 

 between what the older geologists supposed 

 to be widely separated epochs. . . . This 

 truth is further illustrated in a most inter- 

 esting manner by the impartial and highly 

 competent testimony of M. Pictet, from 

 whose calculations of what percentage of 

 the genera of animals, existing in any for- 

 mation, lived during the preceding forma- 

 tion, it results that in no case is the pro- 

 portion less than one-third, or 33 per cent.; 

 . . . other formations not uncommonly 

 exhibit 60, 80, or even 94 per cent, of genera 

 in common with those whose remains are 

 embedded in their predecessor. HUXLEY 

 Lay Sermons, serm. 12, p. 280. (G. P. P., 

 1899.) 



3472. TRANSITION, SCIENCE IN 

 STATE OF Miasma and Malaria but Partial- 

 ly Understood. The term " miasm " has had 

 an extensive and somewhat diffuse applica- 

 tion in medical science. It may happen 

 in the future that typhoid will be classified 

 strictly as a miasmatic disease. But at 

 present, in the transition state of the sci- 

 ence, it would hardly be justifiable to clas- 

 sify typhoid with a typically miasmatic 

 disease like malaria. Yet it is clear that 

 mention should here be made of a group of 

 diseases of which malaria is the type, and of 

 which the tropics generally are the native 

 land. The bacterial etiology of the group is 

 by no means worked out. The cause of ma- 

 laria alone is not yet a closed subject. How- 

 ever the details of the etiology of this group 

 finally arrange themselves, there is little 

 doubt of two facts, viz., the diseases are 

 probably produced by bacteria or allied pro- 

 tozoa, and soil plays an important part in 

 their production. NEWMAN Bacteria, ch. 5, 

 p. 177. (G. P. P., 1899.) 



