42 IOWA GEOLOGICAL SURVEY 



only of unremitting toil, may be won by those who have been 

 willing to suffer, endure, and devote lifetimes to the discovery of 

 a small number of new truths. Ars longa, vita brevis. It is 

 characteristic of science to be content with slight advances that 

 may be slow as the precession of the equinoxes, if only they be 

 sure; and the utmost that even the most patient and ingenious 

 worker can achieve is to contribute but one little stone or two 

 towards the building of that stately edifice in which Truth may 

 dwell. Yet that little is enough. For Truth, no less than Wis- 

 dom, as saith the Preacher, "exalteth her sons, and taketh hold 

 of them that seek her. He that loveth her loveth life ; and they 

 that seek her early shall be filled with gladness. . . . For at 

 first she will walk with him in crooked ways, and will bring fear 

 and dread upon him, and torment him with her discipline, until 

 she may trust his soul, and try him by her judgments : then she 

 will return the straight way unto him, and will gladden him, and 

 will reveal to him her secrets. If he go astray she will forsake 

 him, and give him over to his fall." 



In palaeontology, though our knowledge has indeed grown 

 apace, it is still uncertain and confused in places, and in others 

 there are distressing voids. The present state of this special 

 branch of science may be likened, even as archaeology has been 

 likened, to a mosaic of colored tesserae, which, though broken 

 here and there, yet shows broad patterns and many curious de- 

 tails. Scattered in the surrounding debris and sometimes buried 

 by this are the little cubes waiting to be found and fitted into 

 their proper places. For the parts of the mosaic now complete, 

 we have to thank the explorers of the past, for the filling in of 

 the lacunae, the explorers of the future. And we may be assured 

 that future laborers, with broader knowledge, better training and 

 greater means of investigation must eclipse all that the ablest 

 workers of our generation can accomplish. Content as every 

 earnest naturalist is to serve so pure and unapproachable a 

 mistress as Truth, let each join in the hope that those who come 

 after us, more favored than ourselves, may be permitted to hold 

 some converse with the Sphinx ! 



Finally, before passing from these general reflections to our 

 special province, two thoughts may be singled out from the rest 

 because they bear closely upon the real concerns of humanity, 



