INTRODUCTION. 



xix 



tigations are to be pursued. They will need patient labour and careful observation ; 

 but if these are given they will probably be successful. What the Synopsis fails 

 to give, the specific descriptions and plates will probably supply; and the List of 

 Families, Genera, and Species, which follows, will enable the student to reduce his 

 scattered materials into their proper order, and arrange his plants in the herbarium 

 according to their scientific classification. 



It is true the difficulties increase as the inquiry proceeds. It is easier to find 

 tbe generic than the speciftc name of a plant; to trace it home to its family, than 

 to identify it as an individual. But those who have accomplished the one are little 

 likely to rest satisfied without attempting the other. And if a real difficulty occurs, 

 surely some more advanced naturalist- friend can always be got hold of to throw 

 light on the subject. For brotherhood is strong among them— especially among 

 the highest — whose readiness to help the ignorant, even at the expense of much 

 valuable time and trouble, is an example which all will do well to imitate. On the 

 other hand, the '■Hgnorant'' should carefully guard from presuming on such good 

 nature. A habit of recklessly sending unexamined specimens to be named — a dozen 

 of one sort perhaps — cannot be too strongly deprecated. But a real difficulty, which 

 the possessor of a plant has tried in vain to surmount, is sure to be kindly and 

 considerately met by any one to whom reference is made. 



Very little more remains to be said, except on the subject of microscopic examination. 

 In the course of these descriptions, especially in the latter ones, certain characters 

 of plants, or the plants themselves, are described as microscopic objects. And it 

 was necessary to state this, in describing such species as are only distinguishable 

 from each other when observed through a power of the microscope high enough to 

 reveal internal structure (see Plates LXXVIII. LXXIX. and LXXX). A microscope, 

 therefore, is one of those desirable possessions which almost amounts to a necessitv, 

 and is absolutely such to a student who intends to investis^ate thoroughly for himself. 

 The internal tubes of a PolysipJionia, for instance (Plate XXV., &c.), cannot be seen 

 without it, any more than the diff'erences among Lynghjas, Microcoleus, Oscillatorias, 

 Monormia, &c. (Plate LXXVIII., &c.). And in days when an actually useful instru- 

 ment may be had for 10s. 6d., and very good ones for a few pounds, it is to be 

 hoped that few will be unable to afford themselves the luxury of such an assistant. 

 For a luxury that is, indeed, which will so often resolve perplexing doubts by a 

 glance, and save many weary hours of uncertain labour. 



Connected with the microscope is, of course, the subject of examining plants by 

 making sections of them. The G-ermans call a section a durcJischnitt, or thorough- 

 cut — expressively enough; and this durchschnittiiig is a necessary accomphshment to 

 an advanced, i.e. a scientific student. Some genera even are wonderfully alike, till a 

 durchschnitt reveals a diff'erence in internal structure; when, behold, plants which 

 might be taken for twin brothers have to be separated as wide as the poles, and 

 the fructification of algae can never be understood without such minute dissection. 

 And although in these descriptions internal structure is not really entered into, 

 except in cases which are visible by simple observation under a microscope, necessary 

 allusions to it have been occasionally made,* which seem to render it desirable to 

 * As in the characteristics of Family XIV., Squamnrics, &g. 



