218 LECTURES OS 



only about a line in length and a few hundredths of an inch across, 

 which crawl about browsing- on the minute algse and nullipores, or 

 quietly inhaling their infusorial food; and also the hunting grounds 

 for equally tiny but predacious tribes which feed upon their vege- 

 tarian neighbors. Of all these, and especially the very interesting- 

 tribe of Caecidse, full particulars will be found in the "Descrip- 

 tive Catalogue of the Mazatlan Mollusca." 



The foregoing is offered as a sketch of an investigation carried on 

 by an ordinary student without scientific name or talents, in order to 

 show that any one of ordinary patience and accuracy may do some- 

 thing to advance our knowledge, of the works of God. It is by en- 

 deavoring to work out one province carefully, however humble that 

 province be, that the interests of science are best advanced. There 

 is no one but^ias the materials for some branch of inquiry within his 

 reach; he has only to make choice, educate his eye, observe patiently, 

 and be faithful. Those endowed with the peculiar faculty for elimi- 

 nating and combining already existing details, may construct the 

 beautiful fabric of general truths; but if this be attempted before we 

 have obtained the facts with sufficient accuracy, the fabric must 

 crumble away. The humblest fact duly placed in connexion with its 

 kindred facts, is of far more value than a grand but hasty generali- 

 zation. The coral polypes build more islands than the volcanic fires. 



The noble science of Geology, ably defined as dealing with un- 

 limited time as Astronomy deals with space, cannot be prosecuted 

 with certainty without the study of recent shells, especially in con- 

 nexion with their station and geographical distribution. The micros- 

 copic species of the Tertiary formations have lately been much 

 studied in Europe, and will, doubtless, soon meet with the attention 

 they deserve in the vast beds of this continent. These will have to 

 be carefully compared with existing forms, both in the Caribbean and 

 "West American faunas, and it is not improbable that facts may be 

 eliminated from thern not less important than the discovery of the 

 Atlantic Malea ringens before quoted. The study of recent and of 

 fossil shells are but branches of the same inquiry, like the study of 

 the fossils of two consecutive formations. No one department can be 

 safely investigated without a knowledge of the others, anymore than 

 one existing geographical fauna can be ascertained without the rela- 

 tions supplied by other faunas. To the ordinary student a general 

 knowledge of the whole subject, as it is presented in time and space, 

 should lay the foundation for the special knowledge of his particular 

 department. By this means his study of the details will bo conducted 

 in an enlarged spirit, and presented in that form in which it can best 

 be collated with other ascertained facts. 



The study of Natural History is commended not only to those of 

 leisure and abundant resources, but especially to those busily oc- 

 cupied in the works and cares of life. 



-" Nature never did betray 



The heart that loved her; 't is her privilege, 

 Through all the scenes of this our life, to lead 

 From joy to joy. For she can so inform 

 The mind that is within us, so impress 



