134 THE JOURNAL OF BOTANY 



seems to me to be an almost perfect specimen of what a systematic 

 monograph on any group of organisms ought to be. We have in 

 the first place an introduction, dealing with the general character 

 and life-history of the group ; then comes a synopsis of the orders 

 and list of the genera ; then we have prefixed to each order a key 

 to the genera, with woodcuts illustrative of each genus ; then to 

 each species is devoted an elaborate description with a reference 

 to its synonyms and literature, together with a description of its 

 habitat. The student is thus guided in the most gentle and 

 illuminating way through the intricacies of the subject. 



The labour involved in the revision of the work by Miss Lister 

 has been greatly increased by the adoption of the Rules of Nomen- 

 clature which were revised in 1905 ; so that whereas in the first 

 edition the custom was followed by which the first authentic 

 specific name published under the genus in which the species 

 then stood took precedence of all others, in the new edition the 

 rule has been adopted that the earliest specific name, under 

 whatever genus it may have been published, is to be used. Further- 

 more, the rule was adopted that the starting point of these names 

 as well as for those of the genera of Mycetozoa should be the 

 Species Plantarum of Linnaeus, published in 1753. The result of 

 these two rules has been to involve an enormous amount of labour 

 in examining the literature bearing upon each species, a labour 

 painful not only from its magnitude but from its destructive 

 character. Some of the old and familiar genera, such as Ghondrio- 

 derma and Spumaria have disappeared, and many of the most 

 familiar species appear under most unfamiliar names, so that the 

 change is something of a shock to those who have been accustomed 

 to the use of the first edition. Every naturalist knows that, as 

 a sense of affection grows up towards the objects of his study, 

 so the very names of those objects have the association of old 

 friendship and are loved almost as the objects themselves. We 

 are sure that Miss Lister must have suffered much from the 

 disruption of old associations. 



The comparison of the two editions may throw some light 

 upon the advance made in the study of this group. The intro- 

 duction dealing with the life-history of these organisms is sub- 

 stantially unchanged, a fact which seems to indicate that no great 

 advance has been made in this subject. On the other hand, the 

 addition of something like sixty species to the one hundred and 

 eighty or thereabouts of the first edition shows how much progress 

 has been made in the recognition of new forms, an advance pro- 

 bably not a little owing to the first publication of this book and 

 to the labours of its authors. 



There have been added to the contents of the first edition 

 an additional list of synonyms, a list of species to be discarded, 

 a bibliography, and a glossary : the magnitude of the material 

 to be dealt with may be gathered from the fact that the biblio- 

 graphy occupies no less than eight pages. Another point of 

 difference between the two editions is the presence in the new one 

 of one hundred and twenty coloured plates, reproduced by the 



