Biologie. — Morphologie etc. 373 



excelsa., wie näher beschrieben wird, in viel höherem Grade als es 

 in den Floren angegeben wird. Grevillius (Kempen a. Rh.). 



Petersen, H. E., Om Mangelen af de for Umbellifererne 

 ejendommelige ö vre aborterede Aeg hos Hydrocotyle. 

 [Summary in English: On the wanting ofthe Upper a bor- 

 te d ovules in Hydrocotyle L.]. (Biol. Arb. tilegn. Eug. Warming, 

 p. 151 — 158. 9 fig. Köbenhavn 3 Nov. 1911.) 



In young fruits of Umbelliferae four ovules are found, but during 

 the development the two Upper ones abort. Yet in Hydrocotyle 

 vulgaris, swidaica and bonariensis the Upper ovules are wanting, and 

 in examining the development of the fiowers of the first named 

 species the author has found no trace of the Upper ovules. It is cha- 

 racteristic for Hydrocotyle that the Spaces in the ovary are but 

 small; perhaps there is a connection between this and the reduetion 

 of the Upper ovules. 



The wanting of these aborted ovules may contribute to corrobo- 

 rate the interpretation of Hydrocotyle as a genus of the Araliaceae, 

 in which family several genera lack the upper aborted ovules. 



Ove Paulsen. 



Pool, R. J., Histological studies in the Artemisia formation' 

 Univ. Nebr. Stud. VIII. p. 1—28. pl. 1-8. Oct. 1908.) 



The leaf strueture of plants of the Artemisia formation is com- 

 pared, and it is found that there is a marked predominance of pali- 

 sade over spongy tissue, also a diminution of intercellular Spaces, 

 which are frequently reduced to mere lines. Water-storage tissue is 

 present in nearly all ofthe species investigated. Detailed descriptions 

 and figures of many species, especially Artemisia tridentata and 

 Juncus balticus are included in the paper. M. A. Chrysler. 



Raunkiaer, C, Statistisk Undersögelse over Variationen 

 i Bladstilling hoskoglerne af Rödgran (Picea excelsa). 

 [Statistical examination ofthe Variation in the para- 

 sticha of cones of Picea excelsa]. (Bot. Tidsskr. XXXI. 2. p. 

 121—126. Köbenhavn 1911.) 



In examining 2000 cones of the common spruce from the neigh- 

 bourhood of Copenhagen the author has found that in 95.65 per- 

 cent the conspieuous parasticha belong to the series 5, 8, 13...; 

 of these 81.2 percent have the Position 8 / 21 , 1.7 percent have 13 / 34 , 

 1.5 percent 21 / 55 and 11.3 percent n l 29 . — 2.35 percent of the 2000 

 belong to the 4, 7, 11 . . . series, of these 38 have the position 5 / 18 , 

 5 have s / 29 , 3 have 13 / 47 and one only 7 / 25 . — In three cones the 

 conspieuous parastichs is 5, 7, 12 . . ., of these two have the position 

 13 / 21 and one 8 / 19 . — 33 cones belong to the 4, 6, 10... series. here 

 the scales are opposite, and 4 cones belong to the 3, 6, 9... series, 

 where the scales are verticillate, being situated three together. 



All the numerals are put in a tabular form, and the difference 

 between them and those obtained by AI. Braun is discussed. The 

 cones have been picked up from the ground; as the spruce is not 

 native in Den mark an examination of different trees would be of 

 a slight interest only, but the author emphasizes the importance of 

 observations from countries where the spruce is at home. 



Ove Paulsen. 



