IV PRKFACK. 



Elements of Vegetable Histology are treated of in as 

 simple and brief a manner as was thought to be con- 

 sistent with the nature of the subject. 



The Schedules, the use of which is very strongly 

 recommended, were devised by the late Professor Hens- 

 low, of Cambridge University, to fix the attention of 

 pupils upon the salient points of structure. They will 

 be found invaluable to the teacher as tests of the accu- 

 racy of his pupils' knowledge. The cost of striking off 

 a few hundred blanks of each sort would be very 

 trifling, and not worth considering in view of the 

 resulting advantages. 



The wood-cuts are from drawings from living speci- 

 mens, except in two or three instances where assistance 

 was derived from cuts of well-known excellence in 

 standard works on Botany. It need hardly be said 

 that the engravings are not in any sense intended to 

 take the place of the living plants. They are designed 

 chiefly to assist in the examination of the latter, and 

 whilst it is hoped that they may be of service to those 

 who may desire to read the book in the winter season, 

 it is strongly urged upon teachers and students not to 

 be satisfied with them as long as the plants themselves 

 are available. 



The works most frequently consulted in the prepar- 

 ation of the text are those of Hooker, Gray, Beutley and 

 Oliver. 



Finally, the Authors look for indulgence at the hands 

 of their fellow-teachers, and will be glad to receive sug- 

 gestions tending to increase the usefulness of the work, 

 and to extend a taste for what must ever be regarded as 

 one of the most refining as well as one of the most 

 practically useful of studies. 



September, 1879. 



