Miscellaneous. 295 



in the youngest shoots, enclosed, as before, in a double layer of 

 epidermal cells. 



The author has traced the development of branches from this 

 axis. They are given off from single exogenous wedges in a very 

 peculiar but eminently exogenous manner, the details of which are 

 given in the memoir. But, besides these, other clusters of vessels 

 are given off which have no exogenous development or radiating 

 arrangement. It is not yet clear what these secondary vascular 

 bundles signify. 



The author points out the general resemblance between this de- 

 velopment of the detached exogenous wedges and that of the 

 4-partite woody axes of the Bignonias of Brazil, demonstrating 

 at the same time their very marked differences. 



Though no traces of leaves have yet been discovered in connexion 

 with these stems, the author has very little doubt that they belong 

 to some Lycopodiaceous plant. The nature of the vessels and the 

 simplicity of their ai'rangement alike indicate cryptogamic features, 

 at the same time that their mode of development indicates, with 

 remarkable distinctness, that we have here another example of 

 that exogenous mode of development of which the author has 

 already described so many modifications amongst the fossil stems 

 from the Coal-measures. The occurrence of this physiological pro- 

 cess of exogenous growth in a stem which, when matured, was 

 little more than one tenth of an inch in diameter, shows that its 

 occurrence is not merely a question of the size of the plant, as 

 some have supposed, but that it has a deeper meaning, and corre- 

 sponds more closely than has been supposed with the exogenous 

 developments seen equally in large and small examples of living 

 plants. 



MISCELLANEOUS. 



On a new intermediate Type of the Sublcingdom Vermes (Polygordius ?, 

 Schneider). By M. Eduond Perkier. 



The study of intermediate types becomes of more and more im- 

 portance in proportion as one knows more of the organization of 

 the creatures constituting the great primary groups of the animal 

 kingdom. The number of these types, formerly very limited, 

 becomes every day greater as the means of investigation and the 

 naturalists devoted to the study of the organization of animals 

 become more numerous. The subkingdom Vermes has proved 

 particularly fruitful in this respect, so much so that, besides the 

 great classes that every one knows, it has become necessary to 

 create small classes to receive some creatures still completely isolated 

 in existing nature — such as the Sagittce, Balanoglossi, Pohjgordii, 

 and many others. I had the good fortune at Itoscoff, in the products 



