BY J. J. FLKTCHKR. 877 



The apparent scarcity of seedlings of the above four species 

 during the past season may have been due to seasonal drawbacks; 

 and I hope, at some future time, to be able to examine better 

 series. 



P. myrtilloides Sieb. — I failed to find a single seedling. A 

 few embryos examined gave 4-5. ]n the Baron's list this species 

 is credited with 4-6. 



Of the total of 61 species of Persoonia, four are known habit- 

 ually to produce dicotylous embryos, 24 to produce polycotylous 

 embryos, leaving the condition in 33 still open for investigation. 

 Experience seems to justify a doubt that all these 33 species will 

 turn out to have dicotylous embryos. 



In their very suggestive paper " On the Origin of Angio- 

 sperms,"* Newell Arber and Parkin remark — "During the course 

 of evolution there would seem to have been considerable ' play 

 upon,' or modification of, every unit of the flower. And this 

 appears to us to be true also of the embryo. Late, or far from 

 primitive adaptations are to be found among embryos, just as 

 among flowers.' Persoonia seems to be a case in point, for even 

 in the present incomplete state of our knowledge, it furnishes a 

 very striking series of illustrations of one phase of the " play of 

 variation" upon the embryo — a " play " which seems to be still 

 in progress. 



As to whether the well-marked tendency in so many species 

 to produce polycotylous embryos is a primitive or an acquired 

 character, the following considerations seem entitled to carry 

 weight. 



(1) There is the possibility, suggested by the discovery of two 

 cotyledons in the embryo of the Mesozoic Cycadophyte, 

 Bcnnettites, " that the dicotylous condition was a primitive 

 feature of the great majority, if not all Spermophyta." The 

 evidence irv favour of this view is admirably summarised and 

 discussed by Newell Arber and Parkin in the paper quoted (op. 

 cit. pp. 71-73). 



*Jour. Linn. Soc. Botany, xxxviii., p. 72, 1907. 

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