130 Mr Willis, On Gynodioecism, with a note upon [Nov. 27, 



the observations above, and of the improbability of them all 

 having died, it seems quite likely that they have done so. 



Similar facts are given in the preceding papers (see especially 

 the case mentioned in 2nd paper, p. 19). 



Various observations have been made on other gynodioecious 

 plants, chiefly for purposes of comparison with the work of other 

 writers upon this subject. A few of these are worth recording 

 here. 



Capsella Bursa pastoris, Moench. — On March 12, 1893, speci- 

 mens of this plant were observed on a wall near Grantchester 

 Church, bearing female flowers only, and on April 16th, at 

 Clayhithe, similar plants were found by Mr Burkill and the 

 author. 



The Grantchester plants had just begun to flower, and showed 

 an almost total abortion of the stamens. The Clayhythe plants, 

 however, possessed stamens which were often fertile, but too 

 short to reach and pollinate the stigma. Every stage from fully 

 female flowers with aborted stamens, to normal hermaphrodites, 

 was observed upon these plants. The lowest 15 — 20 flowers 

 in some racemes were unfertile ; above these were a few that 

 had set small shrivelled -looking capsules, and then came fully- 

 developed fruit, with normal flowers above. 



In November of the present year, racemes of Capsella were 

 again found bearing female flowers. Their presence would thus 

 seem to be dependent upon the light or temperature. 



Capsella may thus, under certain circumstances, appear gyno- 

 monoecious or possibly gynodioecious, as has indeed been observed 

 already by Breitenbach\ 



Hippuris vulgaris L. — Plants have been observed in the Ouse, 

 near Ely, bearing female flowers only. It has been recorded^ 

 as dioecious, but the author has not seen any but hermaphrodite 

 and female plants. 



Asperula cynanchica L. — This plant, growing upon the steep 

 dry bank of the Cherryhinton chalk-pit, exhibits the two forms 

 described by Mliller^^. On July 30, 1892, and again on August 5, 

 1893, it was observed that the bulk of the flowers were female, 

 with small aborted stamens. 



Scabiosa arvensis L. — The gynodioecism of this plant is well 

 known. Miiller describes it in such a way as to give the idea 

 that the female form is frequent, if not abundant, in Low Ger- 

 many. On the other hand, it appears from the recent obser- 

 vations of Macleod* that the female form does not occur at all 



^ " Einige neue Falle von Bliitenpolymorphismus." Kosmos 1884, p. 206. 

 - Kirchner, " Flora von Stuttgart und Umgebung." Stuttgart (Ulmer), 1888. 

 * " Fertilisation of Flowers," English edition, p. 302. 



■* " Over de bevruchting der bloemen in het Kempisch gedeelte van Vlaanderen." 

 Botanisch Jaarboek, Gent, v. 189.S, p. 394. 



