Preface. vii 



I desire to offer my most grateful thanks to Professor 

 Herdman, D.Sc., for constant advice and help freely given 

 on all occasions, for his kindness in reading the zoological 

 chapters, and for many suggestions with reference to the 

 subjects dealt with therein. My thanks are also due to 

 Professor Lodge, D.Sc., F.R.S.,for similar services rendered 

 in the chemical and physical sections. To my friend Mr. 

 G. G. Chisholm, M.A., I am indebted for much help and 

 criticism of a more general nature during the passage of the 

 book through the press. I desire also to express my best 

 thanks to gentlemen and firms who have been so kind as to 

 allow me to make use of figures from various publications 

 written by or belonging to them, more especially to Professor 

 Marshall, F.R.S., and Mr. Hurst, of Owens College, the 

 Clarendon Press, Messrs. Cassell and Co., Messrs. A. and 

 C. Black, and the publishers of Van Tieghem's Traite de 

 Botanique and Claus's Traite de Zoologie, and of Luerssen's 

 Grundzuge der Botanik. I have been careful t.o indicate in 

 all cases the source from which I have borrowed figures ; 

 those not so distinguished are original. 



My indebtedness to the many works on Botany and 

 Zoology already published in our own or other languages 

 will be manifest to all. I have not directly expressed that in- 

 debtedness by footnote references, simply because a student, 

 it seems to me, wants fust of all a certain general acquaint- 

 ance with his subject before entering on the task of consulting 

 special memoirs, and the larger text books on the two sub- 

 sciences of Botany and Zoology such as the works of Van 



unnaturally commence among the terms applied to the reproductive 

 products where the greatest chaos prevails. I have already given 

 reasons for the adoption of terms similar to those employed in the text 

 in a paper on the subject (Proc. Liverpool Biol. Soc. vol. ii. p. 112). 



a 



