I may quote from a letter addressed to Griffith by von Martius of Munich, since it couples his own opinion and that of Robert Brown. "He (Brown) agrees with me in appreciating your spirited and enlightened investigations, and I now more than ever look forward to you as his successor—as the standard English botanist."

Only an outline of the nature of Griffith's scientific work with some details on selected subjects can be attempted here. His published works in the Transactions of the Linnean Society and elsewhere, important as they are, represent only a small fraction of his observations. But the wisdom and liberality of the East India Company has put us in possession of his unpublished notes and drawings (bequeathed with his collections to the Company) in the posthumously published volumes of Notulae ad plantas Asiaticas with the accompanying sets of plates. Though his papers were not ready or intended for publication in this form and suffer from having had to be arranged by another hand, they afford, together with his published work, a particularly good picture of how the problems of morphology and classification presented themselves to a keen investigator at this time.

Of his purely systematic work I shall not speak at length. In addition to smaller papers the most important contribution was his illustrated monograph on the Palms of British East India. In the Notulae numerous species are described and figured nearly always with reference to the morphology and physiology of the parts concerned. It is his investigations made with direct reference to morphology and reproduction that claim our attention most. In dealing with them it is convenient to treat of the main questions to which he directed his attention rather than of the separate papers. I shall call attention first to his work on the flower and on fertilisation in a number of plants, then to his observations on Cycas, and lastly to his work on the Cryptogams.

Interest in the structure of the ovule and the nature of fertilisation was widespread at the time Griffith worked. A few years previously Robert Brown had laid the foundations of the scientific study of the ovule and the behaviour of the pollen tube, and during Griffith's time the papers of Schleiden, which extended the comparative study of the ovule and advanced the important though erroneous view that the embryo originated inside the embryo-sac from the tip of the entering pollen tube, were appearing. Schleiden's text-book did not appear until too late to be known to Griffith. His interest was keen on continuing the work, that Brown had begun, on plants that only a resident in the tropics had the opportunity of studying properly, and the first volume of the Notulae, with the accompanying Icones, and the more systematic volume on the Monocotyledons and Dicotyledons contain his unpublished observations on the ovule and flowers of many plants.

His first paper in the Linnean Transactions was on the ovule of Santalum. Griffith observed and rightly interpreted the free prolongation of the embryo-sac from the nucellus, and described the application of the pollen tube to the summit of the embryo-sac, the development of the endosperm, and the origin and development of the embryo. He also recognised and figured the great prolongation backwards of the embryo-sac as an empty, absorbent caecum. At first he left the origin of the embryo doubtful, while recognising the advantages of the exposed embryo-sac for settling the question, but later he decided in favour of Schleiden's erroneous view that the embryo developed from the tip of the pollen tube. Griffith also examined the ovules of Osyris recognising the corresponding facts.

Comparison with the figures of Santalaceous ovules in Guignard's later work will serve to show both the magnificent accuracy in observation of Griffith and the limitation, running through all the work of the time, of not recognising the contents of the embryo-sac before fertilisation.

The Loranthaceae was another family on which the development of the embryo-sac and the processes of fertilisation and development of the fruit interested Griffith specially. Not only did he send his results home to the Linnean Society in two papers, but his descriptions and figures of all the species described in the Notulae take account of these morphological and developmental facts. He traced the development of the cavity of the ovary and regarded the ovules as reduced to their simplest expression—to an "amnios" or embryo-sac. And he observed the extension of the embryo-sacs up the style and the union of the pollen tube with the tip of the embryo-sac. His further description of the development of the embryo, endosperm and fruit is wonderfully exact if we allow for his regarding the long suspensor bearing the embryo as derived from the pollen tube growing down through the long embryo-sac.

Griffith thus recognised all the main peculiarities of Viscum and of Loranthus subsequently described more in detail in European species by Hofmeister (whose analysis of Griffith's work in 1859 is a great testimony to its accuracy) and later by Treub in the tropical species which had been studied by Griffith.

The Balanophoraceae was another group, on which Griffith made pioneer investigations. He collected and examined all the species he met with, partly from the systematic interest in supporting Robert Brown's objection to Lindley's class of Rhizantheae, but still more from his interest in the details of their reproduction. An examination of the plates from his memoirs, only published after his death, in the Linnean Transactions will show how fully he was aware of the structure of the archegonium-like female flower of Balanophora; of the relation of the pollen-grains and pollen tubes to it; and of the appearance of the endosperm which he mistook for the embryo. Throughout he compares the structure with the pistillum (archegonium) of Bryophyta.