Ever yours faithfully,

T.H.  Huxley.

[As for the teaching by “types,” which was the most salient feature of his method, and therefore the most easily applied and misapplied, Professor Parker continues:—­

Huxley’s method of teaching was based upon the personal examination by the student of certain “types” of animals and plants selected with a view of illustrating the various groups.  But, in his lectures, these types were not treated as the isolated things they necessarily appear in a laboratory manual or an examination syllabus; each, on the contrary, took its proper place as an example of a particular grade of structure, and no student of ordinary intelligence could fail to see that the types were valuable, not for themselves, but simply as marking, so to speak, the chapters of a connected narrative.  Moreover, in addition to the types, a good deal of work of a more general character was done.  Thus, while we owe to Huxley more than to any one else the modern system of teaching biology, he is by no means responsible for the somewhat arid and mechanical aspect it has assumed in certain quarters.

The application of the same system to botanical teaching was inaugurated in 1873, when, being compelled to go abroad for his health, he arranged that Mr. (now Sir W.) Thiselton Dyer should take his place and lecture on Botany.

The “Elementary Instruction in Biology,” published in 1875, was a text-book based upon this system.  This book, in writing which Huxley was assisted by his demonstrator, H.N.  Martin, was reprinted thirteen times before 1888, when it was “Revised and Extended by Howes and Scott,” his later assistants.  The revised edition is marked by one radical change, due to the insistence of his demonstrator, the late Professor Jeffery Parker.  In the first edition, the lower forms of life were first dealt with; from simple cells—­amoeba, yeast-plant, blood-corpuscle—­the student was taken through an ascending series of plants and of animals, ending with the frog or rabbit.  But] “the experience of the Lecture-room and the Laboratory taught me,” [writes Huxley in the new preface,] “that philosophical as it might be in theory, it had defects in practice.” [The process might be regarded as not following the scientific rule of proceeding from the known to the unknown; while the small and simple organisms required a skill in handling high-power microscopes which was difficult for beginners to acquire.  Hence the course was reversed, and began with the more familiar type of the rabbit or frog.  This was Rolleston’s practice; but it may be noted that Professor Ray Lankester has always maintained and further developed “the original Huxleian plan of beginning with the same microscopic forms” as being a most important philosophic improvement on Rolleston’s plan, and giving, he considers, “the truer ‘twist,’ as it were, to a student’s mind.”

When the book was sent to Darwin, he wrote back (November 12, 1875):—­