878 ILLUSTRATIONS OF POLYCOTYLEDONY, 



(2) The Proteacece are conceded to be a group of considerable 

 antiquity — a view for which other evidence besides Ettings- 

 hausen's reputed discovery of Persoonia fruits in the Tertiary 

 strata of Baring is forthcoming. It is, therefore, certainly very 

 remarkable, as well as very suggestive, that, out of an Order com- 

 prising about 49 genera and 950 species, only what promises to be 

 the majority of the species of a solitary genus should furnish the 

 sole exception to the statement that dicotylous embryos are 

 characteristic of the Order. I have not been able to find any 

 record of casual deviations from the normal in other Proteads. 

 Among a number of individual seedlings other than those of 

 Persoonia — nothing like a representative series, however — I have 

 seen only one abnormal example, a seedling of Isopogon anemoni- 

 folius with three cotyledons. 



(3) When the four species with dicotylous embryos, and the 

 six species of which only a single fruit was examined, in the 

 Baron's list, are left out of consideration, there remain only two 

 species, P. arborea from Victoria, and P. chamcepeuce which are 

 credited with single numbers (3 and 6). The Baron offers no 

 comment on these cases, nor does he say how many embryos were 

 examined. Further examination is desirable, because at present 

 these species seem to be the only exceptional cases of species 

 which produce potycotylous embryos, in which the number of 

 cotyledons is constant. One would like to have these points 

 settled. Apart from these cases, the experience of later observers 

 has only been confirmatory of Robert Brown's — " I am not even 

 certain that their number is constant in those species in which 

 this anomaly occurs." 



(4) There is the evidence afforded by the not rare occurrence 

 of incompletely divided or bipartite cotyledonary members. 

 Examples of these transitional forms have been furnished in 

 every case in which a fair number of seedlings have been 

 examined. 



When all these matters are taken into account, the conclusion 

 seems inevitable, that polycotyledony in Persoonia represents a 

 departure from the normal— that it is an acquired and not a 



