26 Transactions of the Society. 



in Nicotiana Tahacum. In discussing these two cases of lobed 

 and fragmented nuclei, he expressly remarks that they only occur 

 *' in very old cells shortly before the total disorganisation of the 

 nuclei. Cells with lobed nuclei are therefore distributed between 

 others which have become entirely devoid of a nucleus. Only 

 very rarely does this constriction of a nucleus lead to its complete 

 division. Multinucleate cells are, therefore, only met with very 

 ■occasionally." Strasburger also observed lobed nuclei in the 

 vessels of Bryonia dioica at the time that their membranes are 

 becoming thickened. 



In 1886 a paper by A. E. Grant appeared, which has since 

 been almost entirely overlooked,*' and with which we shall therefore 

 deal at greater length than if it had received due recognition. In 

 this memoir, which is entitled " The Multinucleated Condition of 

 the Vegetable Cell," the author records the occurrence of more 

 than one nucleus in the cells of the following species : — Polygonuwy 

 JSieboldii, Acanthus mollis, Podophyllum peltatum, Eschscholtzia 

 calif ornica, Impatiens noli-me-tangere, Dictamnus fraxinella, Lilium 

 pyrenaicumsiiidFolygonaJu7nmultiflorum. He found the plurality 

 of nuclei in the bast cells, the wood cells and the parenchymatous 

 ground tissue of the stem, and, in the case of Acanthus mollis, in 

 the parenchyma of the petiole. Grant was unable to detect any 

 evidence for the existence of mitosis, and he concluded that in all 

 these cases the multiplication of the nuclei takes place by direct 

 division ; he figures and describes lobed nuclei in support of this 

 view. He took a remarkably broad view of his results, and his 

 paper, which was written thirty-six years ago (having been read 

 three years before it was published), does not deserve the oblivion 

 into which it has fallen. 



Before passing on to the more recent work on multinucleate 

 parenchyma cells, we may deal with a series of observations on a 

 multinucleate condition observed in the young vessels of certain 

 plants. In the development of the larger pitted vessels of the 

 Dioscoreacese, Pirotta and Buscalioni (1898) observed a multi- 

 nucleate phase in the vessel initials. The 'vessels develop from 

 longitudinal series of cells which are at first isodiametric, but 

 -which ultimately become elongated by marked intercalary growth. 

 The nuclei of these elements are at first single, but they 

 subsequently divide so that each cell may finally possess more 

 than a hundred nuclei.f The primary and secondary divisions 

 are all mitotic, but afterwards the process does not always proceed 

 normally. Eventually the nuclei, cytoplasm and parts of the 



* We were unacquainted with this paper at the time that our preliminary 

 note was published, Beer, R. and Arber, A. (1915). 



t Hill, T. G. and Freeman, Mrs. W. G. (1903), give an account of the origin of 

 plurality of nuclei in the root vessels of Dioscorea prehensilis which conflicts with 

 that of Pirotta and Buscalioni, but the Italian observers' work is much more 

 widely based, and its accuracy may probably be accepted. 



