354 Anatomie. — Morphologie etc. — \'anetaten etc. 



10 previous accoants. it is t'oiiiui that tyloses occur in iho sap-wood 

 of all species in which they occur in ihe heart wood. With nspoct 

 to the conifers. true tyloses are tlnind only in Finns. and here they 

 appear to be of normal occurrence. On account oi the laroe pits in 

 the medullary ray cells. ly loses are most frequent in the sott pine 

 gToup. Tyloses are found to be impermeable to such preserving 

 ;ig:ents as creosote, which t'act interferes with the action o\' preser- 

 vaiives, although these niay penetrate into wood elenienis other 

 than vessels. M. A. Chrysler. 



Gow, J, E., Observations on the morpholoüv of the 

 Aroids. ,Botan. Gaz. LVI. p. 127—142. Aug. I^n3.) 



A comparative study of the sporoaenous structures o\' eleven 

 species of aroids indicates that there is no uniformity in the devel- 

 opment of the archesporium, also that the anlipodals vary in niun- 

 ber from three to eleven. The embryo has a spherical forni and 

 lacks the suspensor in eleven genera. hence this type niay be 

 reg'arded as characteristic et the family. A nuniber of other obser- 

 vations are recorded. among which is the production of stamens 

 and carpels on alternate vears bv plants of Jri<(7t'nia trif^fnlluvt. 



^_ M. A. Chrysler. 



Hutchinson. H. A.. The male gametophvte oi Abics. ^^Botan. 

 Gaz. LVn. p. US— 153. Feb. Un4.) 



At the tinie of pollination stalk-cell and body-cell are already 

 formed. and the prothallial cells, \Yhich in Abit-:> baha))U'a are rela- 

 tiveU' persistent, may be as many as t'our. Both stalk-cell and body- 

 cell "mav divido before pollination . and all of ihe nuclei so formed 

 raay pass into the egg cell, as is shown by the occurrence of as 

 many as four extra nuclei in the proembryo. The naclear division 

 resuiting in the formation oi the generative cell and tube nucleus 

 is peculiar, reminding one of the free cell formation which occurs 

 in ascus development. .M. A. Chrysler. 



Harris, J. A.. On differential n\ortality with res pect to 

 s e e d w e i g h t in f i e 1 d c u 1 1 u r e s o f Phaseolus vulgaris. (^ A m . 

 Nat. XLVL^p. 512—525. l<-n2.^ 



The author presents results of a series oi studies on the rela- 

 tionships beiween the weight of seed and its viability. He tinds that 

 there is a differential mortality, both heavy and light seeds being 

 less capable of developing into fertile plants than those seeds whose 

 weight is nearer the mean weight for the type. 



L. O." Overholts (St. Louis). 



Harris, J. A.. On differential mortalitj' with respect to seed 

 weight occurring in field cultures of I'/suni S(7fn'inn. ^Am. 

 Nat.^XLVIII. p. 83-86. 1Q14.) 



A selective mortality is shown here for seeds of Ptsiini sdtivuni, 

 as has been shown by the same author for seeds of F/iasco/us vul 

 garis. There was a tendency in this case for the survival of the 

 heavier seeds, although in 3 experimenis the seeds which produced 

 plants averaged somewhat lighter in weight than those which failed 

 to germinate. L. O. Overholts (St. Louis). 



