ON KAPHIDES. 
571 
of raphides and other crystals in plants. And this is under- 
taken with the more pleasure as affording an opportunity of 
ventilating the question by an abstract of my researches 
thereon_, promulgated piecemeal in various scientific journals,* 
during the last few years, and now to be presented with the 
substance of a few more observations, either since made or not 
heretofore published. Thus, referring for more particular and 
complete details of evidence to those journals, especially to the 
Annals of Natural History , a better digest or more general 
survey of the subject may be given in the Populae Science 
Review than is at present extant elsewhere. Nor is this the 
only object now; for I am not without the hope of exciting 
through its pages more attention to an interesting and valuable 
iepartment of scientific botany, likely to be fruitful in beautiful 
and useful results, and with the additional attraction of novelty 
and facility in the acquisition. 
Let us then, adopting Lord Bacon^s recommendation to 
review our knowledge and transplant it into the minds of 
others as it grew in our own, see how the importance of 
raphides as natural characters became evident to me. During 
many years I had been making dissections under the micro- 
scope, and notes of the results, of every plant collected in 
my rural excursions. These researches were undertaken for 
the purpose mainly of comparing the intimate structure of 
plants and animals, and for learning incidentally what good 
diagnoses might thus be found between allied orders, genera, 
and species. In the natural sciences the study of difference 
or contrast may be more difficult and not less important than 
the study of affinity or analogy ; and the complaint by that 
illustrious philosopher, of the comparative neglect of difference 
in anatomy t is still applicable to modern science. Since the 
discoveries of Schleiden and Schwann, important advances 
have been made in both directions, including the valuable 
characters of the bone-cells and intimate structure of the 
teeth of animals, as expounded by the late John Quekett, 
the late Alexander Nasmyth, and Mr. Tomes. And it had been 
shownj that certain animals may not only be distinguished by 
the red corpuscles of their blood alone from other species of 
the same or allied orders, but from the other members of the 
vertebrate subkingdom generally ; nay, that the most universal 
single diagnostic between the two great divisions of that 
subkingdom is in the blood; that is to say, while a nucleus 
See Amials of Natural History, Quarterly Jo^irnal of Microscopic 
Science, and Seemann’s J ournal of Botany. 
t Lord Bacon’s W orks, 4to., i. 68. 
X See my Appendix to Gerber’s Anatomy, dated 1842, but published or 
printed in the preceding year. 
