18 



POPULAE SCIENCE Is^EWS. 



[Februaut, 1888. 



of which he knows the common name. Suppose he 

 has a tulip: he should begin by examining every 

 part of the plant, and describing it in detail; and 

 when he has satisfied himself that lie has a clear 

 idea of the form of every organ, he turns to the 

 Field, Forest, and Garden Botany, and traces its 

 botanical name by means of the Iseys. If difficulties 

 are encountered, they will arise, in all probability, 

 either from not understanding certain technical 

 terms, or from a misunderstanding of the structure 

 of some organ of the plant. In the former case 

 the glossary should, of course, be consulted; in the 

 latter case the student may learn just what his 

 mistake has been by finding, through the index, 

 where the plant is described, and then tracing it 

 through the key backwards. 



It is a very good practice to take a number of 

 plants of which one knows the common names, and 

 compare them with the family, genus, and species, 

 in the description of the book; looking up the defi- 

 nitions of technical terms as far as may be neces- 

 sary. By this method of rerifcation, as it may be 

 called, not only do we have our attention called to 

 hidden beauties that would otherwise escape us, 

 but we gain a familiarity with botanical phra.ses 

 and the peculiarities of an author, that makes the 

 determination of unknown plants very much easier. 



If the student has access to such costly works as 

 Goodale's Wild Floivers of America or Emerson's 

 Trees and Shrubs of Massachusetts, both of them 

 richly illustrated, he will find that they are admi- 

 rably calculated to serve for study by the verifica- 

 tion method. 



It cannot be too strongly urged, that, in all such 

 work, every part of the plant should be carefully 

 examined before recourse is had to the book. Much 

 of the confusion which beginners experience comes 

 from the practice of reversing this rule. 



A more serious difficulty springs from the minute- 

 ness of many of the parts which a student needs to 

 examine. For the larger sorts of flowers (which 

 a beginner would, of course, naturally start with) a 

 good hand-magnifier and a sharp penknife will 

 bring to view about all that one needs to see ; but 

 for the study of small flowers one should have a 

 dissecting microscope, mounted needles, and such 

 skill in the u.se of them as comes only with practice. 

 In a series of articles published in Wide Awake for 

 1886, the writer has given explicit directions for 

 making a dissecting microscope and the necessary 

 dissecting instruments at small cost, and by means 

 of practical exercises has shown how facility in 

 dissection may be acquired. Given proper tools, 

 the manipulations called for are, in general, exceed- 

 ingly simple. 



In the study of systematic botany it should be 

 the object not only to learn names, and be able 

 to describe the different kinds of plants, but also to 

 appreciate their relationships as shown in their 

 classification into families and higher groups. Let 

 the student begin by learning the primary divisions, 

 and then the distinguishing chai-acteristics of the 

 larger families in each division. Over three-quarters 

 of the flowering plants that we commonly meet 

 are included in about twenty-five large families, 

 and for most of these families the characters are 

 very simple and easily remembered. If special 

 attention is paid to the family characters when 

 plants are studied by verification, it will be found 

 that before long these characters will be impressed 

 on the mind; so that, when anew plant is presented, 

 the student is able very often to tell its family at 

 sight, or at least to tell near what family it belongs 

 in the system. It is no small pleasure to have the 

 satisfaction of thus knowing something of plants 

 that may be entirely new to us; and besides this, 

 we are relieved from using the analytical keys, save 

 in exceptional cases. All this is a very much 



simpler matter to acquire than will appear at first 

 sight. 



The question is often asked, " How can a person 

 remember such a host of names?" All that is 

 needed is, to learn them one at a time, and to have 

 some method of now and then refreshing one's 

 memory. 



First as to learning them. It so happens that 

 most of the words we have to deal with are com- 

 pounded of Latin or Greek roots, and many of 

 these roots are used over and over again, so that a 

 student who learns the meanings of a few of these 

 roots, has a key to the meaning of a good many 

 words. Learning the etymologies is thus one help 

 in fixing the words in the mind. Those who have 

 studied Greek and Latin may have a certain ad- 

 vantage in the matter, but not so great as might 

 seem; for the roots most often used in botanical 

 nomenclature are not the ones which occur most 

 frequently in the classics. All that a student needs 

 to know is how to use a Greek and a Latin diction- 

 ary; and once the habit is formed of looking up 

 the etymologies of new words, it will be found that 

 the insight gained will much more than repay for 

 the trouble. It is the habit of botanical writers to 

 give the etymologies of generic names; and so, by 

 paying attention to these, much dictionary work 

 may be saved. 



In the second place, we would recommend the 

 practice of keeping a sort of floral diary, in which 

 shall be recorded the name and date of first appear- 

 ance of all the plants that are met with throughout 

 the year, in walks or botanical excursions. Such 

 lists are valuable in many ways, besides that of 

 keeping the names fresh in the mind. .\ moment's 

 thought will show how accuracy will be encouraged, 

 and a stimulus given to careful search, and how 

 pleasant reminiscences will be called to mind in 

 looking over the lists of formei- years. 



Although the suggestions which we have so far 

 offered have been applied especially to the study 

 of flowering plants, many of them are, of course, 

 equally applicable to work on the lower groups. 

 A few additional suggestions regarding the.se other 

 departments of the subject may now be given to 

 complete our consideration of systematic botany. 



There are two principal sources of difficulty 

 which render the cryptogams or flowerless plants, 

 as a rule, harder to study than the plants we have 

 been considering. The.se are, (1) the extreme 

 minuteness of the parts to be examined, necessi- 

 tating the u.se of a compound microscope; and (2) 

 the more or less confusing and highly technical 

 character of much of the literature that one is 

 forced to use. Still, it must not be supposed that 

 all the flowerless plants are equally hard to study, 

 any more than we should say the same of flowering 

 plants On the contrary, there are certain groups 

 of cryptogams which may be studied almost if 

 not quite as easily as any of the phjenogams. 



The ferns are a case in point, for to any one 

 who has gained a moderate degree of proficiency 

 in the determination of our wild flowers the study 

 of ferns should present a field as easy as it is de- 

 lightful. It may be invidious to single out a group 

 for special admiration, since each has a charm of 

 its own; but it is diflicult not to grow enthusiastic 

 over ferns. As Thoreau says, it seems as if " na- 

 ture made ferns for pure leaves, to show what she 

 could do in that line." On account of their ex- 

 treme beauty, there has been developed a very full 

 and valuable literature concerning them. In the 

 books beforj referred to, the ferns of the region 

 are included, and in Gray's Manual the student 

 will find their study greatly facilitated by the ad- 

 mirable plates illustrating the generic characters. 

 For works covering the whole region of North 

 America we have Underwood's Our Native Ferns 



and their Allies, in which an introductory part gives 

 all the information that a beginner would need 

 regarding the best ways of studying the group; 

 and Eaton's Ferns of North America, a most mag- 

 nificent work, containing colored plates of all our 

 species. In Hooker's Synopsis Filicum all species 

 throughout the world are described so far as 

 known, and the characteristics of the genera and 

 sub-genera are well illustrated by several plates. 



Whereas in the ferns and their allies a good 

 dissecting microscope is all the optical apparatus 

 that a student needs for the determination of 

 species, in the mosses and liverworts a compound 

 microscope, magnifying from about one hundred to 

 three hundred diameters, is necessary if one would 

 determine more than the characters of certain gen- 

 era. There have been a number of books written 

 on the use of the microscope; and if one must work 

 without a teacher, some of these will need to be 

 consulted. Phin's How to Use the Microscope is a 

 small book, but thoroughly practical. Hehren's 

 Microscope in Botany is more recent and more 

 elaborate, and may be recommended to those who 

 wish to go rather deeply into the subject. 



For those who do not own a microscope, but 

 who would like to learn to recognize the commoner 

 and more easily distinguished genera and orders, 

 the writer has prepared a short Guide to Crypto- 

 (jams that may prove of service. 



Our present authority on the mosses of North 

 America is the work of Lesquereux and James. 

 In this the principal genera are illustrated by sev- 

 eral excellent plates, and the technical terms are 

 defined in a glossary. The key to genera is, how- 

 ever, very unsatisfactory, and the student will do 

 well to use a key recently prepared by Professor 

 Barnes. 



Underwood's Hejiaticce of North America is our 

 most recent work on liverworts. There are no 

 illustrations in this book, but in the old edition 

 of Gray's Manual (1863) the student will find 

 the genera fully illustrated. 



[Special correspondence of the Popular Science Neics.] 



PARIS LETTER. 



For some time hypnotism has been the current 

 topic of scientific talk in many Paris circles. The 

 readers of the Popular Science News have certainly 

 heard a good deal about hypnotism ; but so many 

 misstatements and misrepresentations have been 

 made, that many points require a supplementary 

 information. 



When a proper subject is hypnotized by either 

 of the classical methods, he is made to pass first 

 into a condition of lethargy, during which he is in- 

 sensible to all exterior facts. This period is specially 

 noticeable on account of the ease with which mus- 

 cular contraction is induced in any part of the 

 body at will, by means of a very slight friction of 

 the skin. The subject, in a cataleptical state, is 

 easily brought to a second condition by very simple 

 means, such as a slight touch on the forehead. 

 During this state the subject opens the eyes, and 

 his senses may perform their functions. The whole 

 body, or any part of it, preserves during a long 

 time (fifteen to twenty-five minutes) all positions 

 that are given to it, however abnormal and tiresome 

 they may be. The subject moves about, but with- 

 out much spontaneity. When pictures are shown 

 to him, his face assumes gradually an expression 

 which corresponds with the nature of the picture 

 which is shown, — ^ a sad face corresponding with a 

 sad subject, and a merry one with a merry repre- 

 sentation. During this whole period the eyes are 

 very intently kept upon the objects which they are 

 brought to laear upon; and when a forcible attempt 

 is made to hide them, without furnishing at the 



