Agassiz at 



fossils. Echinodcrms bave great palaeontological 

 importance. They are the best preserved of all fos- 

 sils, and are fouud in the very lowest fossiliferous 

 rocks. They have been found on every geological 

 horizon, and the chain of their existence, as we have 

 it is complete. Darwinists cannot say that the tran- 

 sition links will he forthcoming. Each epoch has its 

 own peculiar, well-marked forms, and there is no 

 transition. 



The order of echinoderms, which figures most 

 prominently in palaeontology is the order of criuoids, 

 or stone lilies. They have a faint resemblance to a 

 star-fish, supported on a pointed stem, which is fixed 

 to the rocks. During the tertiary period and at the 

 present time, there are crinoids without stems, as the 

 comatula. The comatula is not a star-fish, as some 

 text-books say, but it is a true criuoid. The young 

 comatula has a stem, and is attached to the sea- 

 weeds, but it drops the stem when it reaches ma- 

 turity. One interesting fact is that the oldest 

 criuoids were most firmly rooted to the ground, 

 and their arms or rays were very small. In 

 these forms the stem and root elements prevail. 

 In later times the arms become more fully 

 developed, and the animals are less firmly rooted to 

 th,e ground. This progression continues until iu the 

 Tertiary period, and at the present time we find 

 free, moving crinoids with well developed arms, 

 which closely resemble the higher order of star 

 fishes. There is a steady progress from early to later 

 times. This is beautifully shown by the class of 

 echinoderms. We hf>ve tho same picture in their 

 embryology. The older adult forms resemble the 

 embryonic forms of later times. The embryo of 

 comatula is like the adult Silurian crinoid. Such 

 facts as these have led to the misconceptions of the 

 transmutation theory. 



I may say here that- the best sources of knowledge 

 of crinoids are the reports of the American Geo- 

 logical Surveys. 



The constituent or radiating parts of a radiate 

 have been called segments; but we need another 

 word to express this idea. I think I have found a 

 good name fur these fundamental parts of a radiate; 

 it is spheromere, a segment of a spheroidal body. 



In closing his lecture, Prof. Agassiz .--aid: "Do we 

 recognize in the manifestations of physical forces, 

 as heat and electricity, anything indicative of 

 thought and combination? Is there anything that 

 shows that the lowest should be first ? Do we not 

 have in this series which I have indicated an evi- 

 dence of intelligent action which we do not find in 

 physical forces? Nothing but a presiding intelli- 

 gence could produce these wonderful gradations 

 from the simple to the complex. Therefore -I arn 

 opposed to Darwiuidm." 



Penikcse. 53 



AMERICAN GLACIERS. 



THE ICE SHEET WHICH COVERED THIS 

 CONTINENT. 



EVIDENCES OF THE GLACIAL PERIOD IN AMERICA A 

 LECTURE DELIVERED BY PROF. AGASSIZ, AUG. 4, 

 1873. 



LADIES AND GENTLEMEN: The facts by which we 

 recognize the passage of glaciers over our globe are 

 very different in different parts of the globe. Tho 

 parts that have been studied are so different that 

 the evidences are as diverse in Europe and America 

 as we could well expect. This is chiefly owing to 

 differences of climate. The evidences of a general 

 glaciation are best known in Europe, but they are 

 tolerably understood in North America, and hava 

 been observed in South America. They have also 

 been noticed in Asia, Australia, and parts of Africa, 

 and there is no doubt that the whole of our globe 

 was colder than it now is at a time not far remote, 

 geologically speaking. The chief differences be- 

 tween the aspects of glacial phenomena in Europe 

 and America I will endeavor to explain to you. 



Not in Switzerland alone, so admirably exhibited 

 on this map of its mountains made by Guyot, but in 

 the Pyrenees and south of them, in Austria, in tha 

 Caucasus everywhere, the remains of glaciers are 

 found in connection with mountains. Both sides of 

 the Scandinavian ranga are full of great fiords, which 

 extend all round Norway and Sweden, and it is 

 probable that in the north <> Sweden there were 

 formerly great glaciers trending into the White 

 Sea. In 1840 I first explored Scotland, and found 

 traces of glaciers descending from her mountains. 

 There, as usual, I fouud the radiation of great 

 masses of ice from mountain-centers, and yet there 

 were uot wanting indications few, but very telling 

 of still greater masses spread all over the country, 

 without reference to inequalities of surface. For 

 there were marks of glacial action on the tops of tho 

 highest ranges scratches from north to south. Dr. 

 Bucklaud, of the University of Edinburgh, follow- 

 ing my suggestion, first fouud them on the very 

 summit of Shehallion, and to him we owe the first 

 fact of that general glaciation which preceded all 

 other. So, high up on the Scandinavian mountains, 

 scratches are abundant, and all trending South,- 

 ward. 



What are the characteristic features of glaciaX 

 action in this country ? With the exception of evi- 

 dence of a few local glaciers in the White Mountains 

 and elsewhere, all other traces are the marks of a 

 glaciation which has been uniform, and from north 

 to south. Wh<i.n first coming to this country, in 

 1846, we stopped a few hours at Halifax. I ran up 

 from the steamer to the fortress, and there saw what 



