I go NATURAL HISTORY. 



Johnston, a medical practitioner at Berwick-upon-Tweed, 

 and a well-known naturalist. The work by which Dr 

 Johnston is best known is his 'History of British Zoo- 

 phytes,' which appeared in 1838, and of which a second 

 edition was published in 1847. As the Ccelenterate animals 

 were, at the time when Johnston wrote his treatise, but 

 imperfectly separated from other animals, we find here 

 descriptions and figures not only of the British species 

 of the Zoophytes strictly so called (namely, the Sea- 

 anemones, the Sea-firs, &c. ), but also of the Sea-mats 

 and their allies (the Polyzoa). Moreover, it had not at 

 this time been discovered that there was any connection 

 between the jellyfishes and the ordinary plant-like Zoo- 

 phytes, and the former found, therefore, no place in 

 Johnston's work. The ' History of British Zoophytes ' will 

 always have to be consulted by any British naturalist who 

 may be engaged in the study of the particular group of 

 organisms of which it treats; though the several groups 

 with which it deals have now received a much fuller 

 exposition at the hands of modern investigators ( Allman, 

 Hincks, Gosse, &c.). Besides the work just mentioned, 

 Dr Johnston published in 1842, 'A History of British 

 Sponges and Lithophytes,' in which he not only dealt with 

 the sponges properly so called, but also with a number of 

 marine organisms which are now known to be of a 

 vegetable nature. Owing to the exceptional difficulties 

 which attend the study of the sponges, and the compara- 

 tively very limited knowledge possessed by the % naturalists 

 of fifty years ago as to the structure and nature of the 

 sponges in general, this work is not of nearly so much 

 value as the one on the British Zoophytes. 



