BOTANICAL GAZETTE. 242 



rise to spores and tlicse spores in turn produce new vegetative plants. 

 'I'his com|)aratively short phase in the life liistory of the moss whicli 

 we call its fruit, or more properly '-sjjorogone," becomes the {princi- 

 pal ])art of the life of |)lants with precocious reproduction, sucli as 

 l'"cnis, F,([uisetacea3 and Oi)hioglossea3. In these cases the prothallus 

 nt once gives rise to male and female organs, and the resulting "s|)or- 

 ogone'' hy its vigorous growth soon destrovs all traces of the early 

 sexual phase. This primilive thallus becomes more and more 

 subordinated as we advance in the plant kingdom, becoming of less 

 relative size and more and more transient. As we advance the se.xes 

 begin to be separated and the way in which this might have been ac- 

 complished is very ingeniously presented. First the spores themselves 

 become sexual and we have microspores and macrospores and here 

 the prothallus nearly disappears and with it "almost the last trace of 

 the primordial cellular Alga." We would thus lutve both u male and 

 a female prothallus. 



At 1 ist in Phanerogams the microspore or pollen grain produces 

 the "pollen tube" as the rei)resentative ot a male i^rothallus; while 

 the macrospore or embryo sac gives rise to the female prothallus, 

 which we call '-endosperm." 



The whole sut)ject is one of exceeding interest and importance 

 and we now begin to know enough to know that our old i^'eas of the 

 relations of plants hardly deserve even the e|)ithet "crude" and that 

 immense fields of investigation are opening before us the extent of 

 which no man dares to measure — J. M. C. 



How Cro.ss-Fcrtilization is Aided in Soino ri'iiciferjp.— 



In some Crucifcnc the introrse anthers of the long stmiens become ex- 

 trorse before the pollen is shed. In the opening buds of Brassica 

 iatiipcstris and Cardamiiic paitcisccta the anthers of one ])air of stamens 

 — slightly surpassing the stigma — exactly face those of the opposite 

 p nr ; but while the flower is expanding and before the pollen is dis- 

 charged the anthers of each jiair bv quarter twists of the filaments- — 

 one to the riii;ht, the other to the left — are made to {:\.cq in opposite 

 directions, thus virtually becoming extrorse. Moreover, the anthers 

 bend downward, making it still more difficult for any wind shaking to 

 bring pollen in contact with the sti{~;ma. The anthers of the short 

 stamens remain introrse since, the stigma being out of their reach, 

 they can do no harm. — Voi.nev Ratian, San Francisco, Cal. 



S;\lTa(*oni;l ])lll'l)lirea, I- -On June 8lh while collecting a k\v 

 sjiecimens of Sarracrnia f^iirpii'ra, L. . I was surprised on drawing 

 aside the petals to look at the stamens, to see the whole cavity formed 

 by the petals and the peltate expansion of the stvle filled with files as 

 large as the common house-fly. all busy as could be eating the pollen, 

 of which scarcely a grain could be seen. I counted fourteen flies in 

 one flower. They were in no hurry to vacate the premises. There 

 was a shower coming up at the time, but they were evidently there 

 for food. Nearly every plant examined was filled in the Fame way. — 

 ]osi:rif Jackson, Jr., Afi/ll>iny, Mass. 



