238 EIGHTH ANNUAL REPORT OF 



formed and combined. To obtain a knowledge of the plan and pro- 

 cess of oi-ganization, we must begin with the most simple combina- 

 tions, precisely as we would do in the stud}'^ of mathematical analyses, 

 in which the student commences with the least complicated tbrmulce, 

 and gradually proceeds to those of a more involved character. It is 

 for this reason ihat the study of the algoe, or sea-weeds, is of special 

 interest to the physiologist. The framework of every vegetable is 

 built up of cells or little membranous sacks. All vegetable structures, 

 whether wood, bark, or leaves, are formed of aggregations of these 

 cells, cUfferenthr moulded and united. As we pass along the series 

 of organized forms, we may descend from those of a higher to those 

 of a lower complexity, until, in the class of alga?, we arrive at plants 

 of which the whole body is composed of a few cells strung together ; 

 and finally at others, the simplest of organized bodies, whose entire 

 framework is a single cell. Now, it is onl^" by a critical study of 

 these rudimentary forms, and by tracing them into their complex com- 

 binations, that man can ever hope to arrive at a knowledge of the laws 

 of organization. "We .might speak of the importance of a knowledge 

 of the algoe in their application to agriculture and the chemical arts ; 

 but what we have here stated will be a sufficient reason for their 

 -Study, independent of all minor considerations. 



2. The next memoir consists of an account of a series of researches in 

 the comparative anatomy of the frog, by Dr. Jeffiies W3'man, of Cam- 

 bridge, Massachusetts. 



The whole animal kingdom may in one sense be considered as the 

 different development of four separate plans of organization, giving 

 rise to four dilierent classes of animals, viz : the Radiata, the Articulata, 

 MoUusca, and Vertebrata. Whatever discovery is made with regard 

 to the organization of any of the species belonging to any one of these 

 classes, tends to throw light on the organization of the whole class; 

 and it is only by the careful study ol" all the different animals of- a 

 class, and a comparison of their analogous parts, that we can arrive at 

 a' knowledge of the general laws which control the development of 

 the whole. Thus the study of human anatomy is the basis of the 

 investigation of the anatomy of all animals with a back-bone ; and 

 conversely, the anatomy of any animal of this chiss tends to throw light 

 on that of man. 



Dr. Wyman's paper gives an account of a series of elaborate inves- 

 tigations of the nervous S3^stem of a very common, but, in a physio- 

 logical point of view, highly interesting animal. 



The Ibllowing are the several points of the memoir : 



(1.) An anatomical description of the more im})ortant parts of the ner- 

 vous system. 



(2.) Comparisons between them and the corresponding organs of 

 other animals, both higher and lower in the scale. 



(3.) The metamorphoses which they undergo, especially the spinal 

 chord and some of the cranial nerves, showing the existence of a more 

 complete analogy between the immature condition of Batrachian rep- 

 tiles and the class of fishes, than has hitherto been noticed. 



(4.) An application of the facts observed in connexion with the cranial 

 nerves to the philosophical anatomy of the nervous .^^stem, showing 



