Obituary — Professor H. A. Nicholson. 143 



The Monograph of the British Stroraatoporoids will probably be 

 regarded as Nicholson's most important contribution to Paleontology. 

 The dubious character of these fossils is plainly indicated by the 

 various conflicting opinions held about them by many leading 

 palasontologists, and even our author found it needful to abandon 

 his own earlier views of their nature. Nothing daunted, however, 

 he continued his researches, and gathering his materials from the 

 Silurian and Devonian rocks of Britain and North America, also 

 from the Silurian of Esthonia and the Devonian deposits of Germany, 

 he made personally more than a thousand microscopic slides from 

 the specimens. The wonderful variety and beauty of the minute 

 structures shown in these slides were represented in perfect detail 

 in the drawings, made by Nicholson himself, which occupied the 

 twenty-nine quarto plates and the woodcuts in the text of this 

 monograph. As the result of these extended investigations, 

 Nicholson was enabled to show conclusively that the Stromato- 

 poroids belonged to a special division of the Hydrozoa, a relationship 

 which had been already suspected by Lindstrom and Carter. It is 

 satisfactory to know that the gi'and series of specimens and the 

 microscopic sections made from them, which formed the basis of 

 this model monograph on the Stromatnporoids, have passed into 

 the possession of the British Museum (Natural Histor}^), Cromwell 

 Eoad, and we believe that the typical specimens of Nicholson's 

 collection of Graptolites are also in the same institution. 



Professor Nicholson further took great intei-est in the nature of 

 certain anomalous organisms which are concerned in the formation 

 of some of the Palteozoic Limestones, such as Solenopora, Dyb., 

 Ilitcheldeania, Weth., and Girvnnella, Nich. & Eth,, and described 

 and figured them very fully, and he also very satisfactorily cleared 

 up the doubtful points relating to the structure of the genus 

 Parlcerin, Carp. 



But Nicholson's services to his favourite sciences were not confined 

 to original researches, for his Manuals and Text-books of Zoology 

 and Palgeontology may deservedly be considered as important 

 adjuncts to their advancement. They are characterized by clearness 

 and perspicuity of style, and by the number and excellence of the 

 figures and diagrams with which they are illustrated. That they 

 are widely used is shown by the number of editions which have 

 been called for, and in each successive edition there is such a largo 

 amount of additional matter as to entitle the book to be regarded as 

 new. This is well exemplified in the " Manual of Palgeontology," 

 the first edition of which was a single volume of 601 pages and 

 401 figures, whilst the third edition comprises two volumes, with 

 1,624 pages of letterpress and 1,419 figures. Only the first of these 

 volumes, which deals with Invertebrate Fossils, is by Nicholson's 

 own hand ; it is rendered especially valuable to the practical student 

 by the careful descriptions and figures of the microscopic structures 

 of the different kinds of organisms occurring in the rocks, so that 

 they can be recognized in thin sections. This volume is the most 

 complete general work on Invertebrate Palaeontology which has 

 appeared in the English language. 



