VOL. XLVII.^ PHILOSOPHICAL TRANSACTIONS. 181 



bearing heath is the most extraordinary ; as of this are found some plants with 

 male flowers only, others with both male and female flowers separately, and still 

 others with hermaphrodite flowers. What Pere Labat mentions in his Voyage 

 a r Afrique Occidentale should likewise be taken notice of here. This author, 

 after having laid down the difierent methods of impregnating the female palm- 

 tree by the male, says, that this process is not absolutely necessary for the pro- 

 duction of dates ; for being at Martinico, he there saw growing by an old con- 

 vent near the place, where they anchored, a palm-tree bearing dates, though 

 the only one of its kind which was thereabouts. Whether it was male or fe- 

 male, he did not pretend to determine, but was certain, that there then was 

 none, nor had been any, within 2 leagues of the place where it grew. He 

 doubts indeed whether this tree bearing fruit did not proceed from the farina 

 foecundans of the male cocoa tree, which is a species of palm, and which grew in 

 abundance near the tree that bore dates : but he observes, that the stones of 

 these dates did not vegetate, and that those who were desirous of propagating 

 date-trees, were obliged to plant the Barbary dates ; as he believed the others 

 had not the germ proper to produce the tree. From this account it is very ob- 

 vious, that the palm-tree here mentioned, was a female, in which though the 

 fruit ripened, it was in such a state of imperfection, as not to be able to propa- 

 gate its species. In this manner we have eggs furnished by hens without a cock ; 

 but these eggs produce no chickens. What this father says of the female palm- 

 tree's bearing fruit without the assistance of the male, Mr. Miller says, has been 

 fully confirmed to him by several persons : and John Bauhin, an author of great 

 credit, describes and figures the whole fructification of a palm-tree, which he 

 saw growing at Montpelier, and which not only produced branches of male 

 flowers, but also female ones bearing dates. Mr. Ray many years after tells us 

 in his history of plants, that at Montpelier he saw this very remarkable tree men- 

 tioned by John Bauhin. This variety in the fructification of the palm-tree, sin- 

 gular as it may seem, has been likewise observed in some few others. The 

 learned Jungius, in his Doxoscopia, mentioning that class of trees which are 

 male and female in different parts of the same tree, says, " that trees of this kind, 

 when they have for many years, produced flowers without fruit, afterwards pro- 

 duce fruit without flowers. This, he thinks, should be further inquired into." 

 This, since Jungius's time, has been done, and it has been found, that some- 

 times some of the trees of this class are wholly male, while young ; but as they 

 advance in age, they have flowers of both sexes, and afterwards become entirely 

 female. This fact Mr. Miller has frequently himself observed in the mulberry- 

 tree ; and the Chevalier Rathgeb, a gentleman excellently well versetl in what- 

 ever relates to vegetation, has observed, that a large lentiscus, or mastich-tree 



