170 MINNESOTA BOTANICAL STUDIES. 



parasite is such as to justify the statement that they may live ten 

 to twenty years after the parasite has fastened upon them. A 

 common type of structure resulting from the attachment of the 

 parasite to the pine consists of an old branch bent downward, 

 from the infected tip of which numbers of smaller branches stand 

 erect, forming a coarse " witch's broom" (See Plate XVI.). 



Perhaps the most interesting facts in connnection with the 

 history of Razoumofskya^ are those which concern the distribu- 

 tion of the seeds. The single-seeded berries are borne on short 

 stalks curved semi-circularly, from which they are easily de- 

 tached when ripe. The berry is joined to the stalk by a scission 

 ]ayer, which is ruptured by the slightest touch or may be burst 

 away by the action of forces set up in the berry, which also 

 expel the seed. The shooting of the seeds from the berry has 

 been known for many years, and a note of the fact has found 

 place in American text-books of systematic botany, but it has 

 failed of wider recognition. Engler and Prantl remark con- 

 cerning the seeds of the Loranthaceas : " The stickiness enables 

 some seeds falling from branch to branch to become attached ; 

 on the other hand, birds crush the fruits and discard the seed, 

 which is surrounded by a viscid layer." (Naturlichen Pflan- 

 zenfamilien. Theil III. ) Kerner says: "The dissemination 

 of the European mistletoe is effected as in all Loranthaceas 

 through the agency of birds, thrushes in particular, which feed 

 upon the berries and deposit the undigested seeds with their ex- 

 crement upon the branches of trees." (Nat. Hist, of Plants, 

 1 : 205, 1894.) Keeble, the most recent observer who has pub- 

 lished upon the Loranthaceas, says : "The berry-like fruits of 

 the Loranths are technically speaking indehiscent ; yet owing 

 partly to growth of the embryo, partly to weakening of the 

 fruit wall in some species, this latter becomes ruptured on the 

 ripening of the fruits, c. g:, Loi-anthus neelgherrensis L. 

 cuneatus; in others a very slight pressure is sufficient to cause 

 the complete extrusion of the seed, sometimes basally, some- 

 times apically. In all cases the seed slips out, but in Viscum 

 orientale Willd., a gentle pressure will cause the fruit wall 

 to crack and the seed to be jerked out." ( Observations on the 

 Loranthaceas of Ceylon, Trans. Linn. Soc. Lond. 2nd Ser. 

 Bot. 5: Pt. 3, p. 97, 1896.) 



In view of the above statements it is safe to conclude that 

 Razoumo/skya is the only Loranth furnished with a mechanism 



