Toi™^.Kri8Ta'] PROGRESS OF MICROSCOPICAL SCIENCE. 319 



Animal Life at Great Depths in the Ocean. — So m^^ch interest has 

 attacliecl to tliis subject since the publication of Dr. Carpenter's inter- 

 esting report, that the history of the progress of discovery in this 

 direction is especially attractive just now. Those who wish to read a 

 short but well-condensed account of the development of our knowledge 

 of this subject will find it in a paper by M. A. J. Malmgren, in Siebold 

 and Kolliker's ' Zeitschrift ' (April 1st). Beginning with the earlier 

 observations of Sars, Keren, Danielssen Loven, and others, it then deals 

 with the labom-s of Edward Forbes, Dr. Wallich, Milne Edwards, and 

 at last brings us down to the inc[uiries of Carpenter, Thomson, and 

 Gwyn Jeflfrys. 



Structure of the Central Nervous System of Vertebrates. — One of the 

 longest and most important memoirs published on this subject is that 

 by Professor Ludwig Stieda, of Dorpat. It is not very abundantly 

 illustrated, but it gives not only the author's own observations in detail 

 on the whole central nervous system in various animals, but deals 

 critically with those who have devoted attention to this subject, and 

 especially our distinguished countryman, Mr. Lockhart Clarke. It 

 extends over nearly 200 pages. 



Termination of the Nerves in Glands is the title of a fine paper by 

 Professor Krause in the last number of Eeichert's ' Archiv fiir Anatomic ' 

 (April). The author traces the nerves to the follicles of the glands, 

 and sometimes to the cells. 



Tlie Structure and Affinities of Sigillaria. — Principal Dawson's (of 

 Montreal) views on this siibject differ in some particulars from those of 

 Mr. Carruthers, whose interesting papers have appeared in these pages. 

 In a memoir communicated to the Geological Society (May 11th) the 

 following account of the above is given : — With reference to Sigillaria, a 

 remarkably perfect specimen of the axis of a plant of this genus, from 

 the coal-field of Nova Scotia, was described as having a transversely- 

 laminated pith of the Sternbergia type, a cylinder of woody tissue, 

 scalariform internally, and reticulated or discigerous externally, the 

 tissues much resembling those of Cycads. Medullary rays were 

 apparent in this cylinder ; and it was traversed by obliquely-radiating 

 bundles of scalariform vessels or fibres proceeding to the leaves. Other 

 specimens were adduced to show that the species having this kind of 

 axis had a thick outer bark of elongated or lirosenchymatous cells. 

 The author stated that Professor Williamson had enabled him to 

 examine stems found in the Lancashire coal-field, of the type of 

 Binney's Sigillaria vascidaris, which differed in some imj)ortant points 

 of structure from his specimens ; and that another specimen, externally 

 marked like Sigillaria, had been shown by Mr. Carruthers to be more 

 akin to Leindodendron in structure. These specimens, as well as the 

 Sigillaria elegans illustrated by Brongniart, probably represented other 

 types of Sigillarioid trees, and it is not improbable that the genus 

 Sigillaria, as usually understood, really includes several distinct 

 generic forms. The author had recognized six generic forms in a 

 previous paper, and in his ' Acadian Geology ; ' but the type described 

 in the present paper was that which appeared to predominate in the 



