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appear as if even species & varieties graduated into each other in all characters, even in fertility when crossed.—

Digitalis possibly after consulting Lindley & Henslow Pamphlets

Genus Primula acaulis & vars. It has been elsewhere shown on evidence, which to my mind seems ample that the oxlip, cowslip & primrose are undoubted varieties descended from one parent stock. Gærtner laboriously experimentised on these vars, (Used in Chapter IV. p. 69) having cross impregnated during several 4 years only no less than 170 flowers! & yet strange to say he seems only twice to have succeeded in getting any good seed (Bastarderzeugung Table p. 721. but this table can hardly be quite correct for a cross is mentioned at p. 247 not here introduced). Gærtner according to his usual system seems to infers from this that these forms are one true species.

But, notwithstanding that he expressly specifies that these plants of this Family offer no difficulties in impregnation, & notwithstanding his immense experience, I cannot avoid the conclusion that in this & in the following case of Anagallis there must have been some error or something makes one in the act of fertilisation in period or manner omitted.

The Anagallis cœrulea & arvensis used in Chapt 4. p. he experimentised on 19 flowers (& Bastarderzeugung p 309) but obtained no seed whatever: as evidence, notwithstanding the array of opposed authorities, seems very good that these are

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only varieties. I [illeg] nor should I have introduced this case & that of the Primrose, had it not been to show how cautious one must should be in drawing inferences on the nature of species from their capacity of crossing being crossed by artificial means.—

Under the same point of view the lessened fertility fact might have be adduced that Gærtner crossed 39 fertilised 39 32 flowers of undoubted varieties of the common garden pea with the pollen of undoubted varieties, (& likewise some flowers of Kidney Bean) & did not in one single case obtain full fertility; but the acknowledged difficulty of manipulating (to which I can bear witness) renders it the Leguminosæ destroys all the interest of the case.

(p (18

We now come to a much more interesting case, that of maize. Gærtner impregnated 13 female flowers on 13 plants of the dwarf Zea maize with yellow seed. (*Zea minor semine luteo." (Bastarderzeugung p. 87, p. 169) with the pollen of the great maize with red seed (& it seems from the Table that other experiments were tried, altogether on 22 female heads);

Only one head single head & set five any good seed; with maize & that head bore only five. good seed. Though these plants are monoœcious monoicous, & therefore easily cross impregnated present no difficulty as far castration is concerned I shd have suspected, so surprising does the result appear, that here also there must have been some error or accident