THE OVULE AND FERTILISATION 185 



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 con- 

 tinuing 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 accom- 

 panying 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 Monocotyledons and Dicotyledons contain his unpublished 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 de- 

 scribed 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 ex- 

 posed 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 develop- 

 ment 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 de- 

 scribed in the NoUdae 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 



