Fig. 2. Wood cut. Mr. G. N. Oliver. Figs. 3-6. Line blocks. Messrs. Andre, Sleigh & Anglo, Ltd. Figs. 7 and 8. Line blocks, reproductions of a wood engraving. Mr. C. Butterworth. Fig. 9. Line block. Figs. 10-13. Line blocks, reproductions of wood engravings. Fig. 14. Line block. Fig. 15. Line block. Messrs. Andre, Sleigh & Anglo, Ltd. Fig. 16. Line block. Swan Electric Engraving Co., Ltd. Fig. 17. Line block. Messrs. Andre, Sleigh & Anglo, Ltd. Figs. 18-20. Line blocks. Figs. 21-23. Line blocks. Messrs. Bourne & Co. Figs. 24 and 25. Line blocks. Fig. 26. Line block. Messrs. Bourne & Co. Fig. 27. Line block. Figs. 28 and 29. Line blocks. Messrs. Andre, Sleigh & Anglo, Ltd. Fig. 30. Line block. Mr. C. Butterworth. Fig. 31. Line block. Messrs. Andre, Sleigh & Anglo, Ltd. Fig. 32. Line block. Mr. C. Butterworth. Figs. 33 and 34. Line blocks. Figs. 35 and 36. Line blocks. Messrs. Andre, Sleigh & Anglo, Ltd. Fig. 37. Line block. Messrs. Bourne & Co. Fig. 38. Lithograph reproduced by the Swelled Gelatine Process. Artists Illustrators, Ltd. Tailpiece, p. 86. Line block. Messrs. Andre, Sleigh & Anglo, Ltd. PREFACE Modern scientific publications, although they may in some or even many cases equal in their scientific quality the memoirs of earlier workers, do not, on the average, reach a high standard as regards illustration. For instance, in Great Britain botany is pre-eminent in its morphological aspects; it should therefore follow that the illustrations, which form so important a part of such papers, should be beyond reproach. This is not always so, a fact which must be patent to anyone with the slightest critical knowledge who looks through a typical journal. This is a fact much to be regretted, since many of the earlier scientists were accomplished draughtsmen and, indeed, often artists; in this connection the Hookers and Professor Daniel Oliver may be mentioned. The implication is not intended that there are no good amateur draughtsmen nowadays; there are, and in some cases possessed of great ability. The beautiful work of Church in his Floral Mechanisms may be cited as an example. It may, of course, be argued that any picture which serves to illustrate the particular feature is good enough; this is the contention of one who takes an insufficient pride in his work. A feature worthy of an illustration deserves the best the author can produce, more especially as a literary form is still, fortunately, preserved or, at any rate, aimed at.