IOWA ACADEMY OF SCIENCES. 149 



Priemer 3 states that peculiar hairs, epidermal cells, crystals 

 cystoliths are of value for diagnostic purposes in the order 

 Ulmaceae. 



Bordet* has made some anatomical studies of the genus 

 Carex. He concludes that in this genus anatomical characters 

 do not offer any material aid in the separation of species. 

 Although some good characters are found in fibro-vascular 

 bundles. 



Mez, who has made an exhaustive study of cystoliths and 

 anatomical characters found in the sub-family Cordieae of the 

 order Borraginaceae, finds that hairs are very characteristic 

 and are certainly valuable from a systematic standpoint. Nor 

 should we omit in this connection the valuable paper by Sol- 

 ereder 5 on the value of the wood structure in dicotyledonous 

 plants, Holle 6 who has made an exhaustive study of the order 

 Saxifragaceae calls especial attention to the structure of pith 

 cells of Gunoniece, the characteristic wood cells in certain gen- 

 era, and crystals in the tribe Eydrangeae. 



K. Leist 7 who has likewise made a study of Saxifragaceae 

 concludes that the species of this order offer characters which 

 makes it easy to separate them into groups, but this grouping 

 does not always conform to the present systematic position of 

 its members. Nevertheless general harmony prevails between 

 morphological and anatomical characters as to species. 



Several other authors Christ 7 , Thouvenin 8 , Waldner 9 

 and Engler 10 have likewise studied this order with reference to 

 different organs and parts. 



3 Cber seine unter Lietung von Prof.Prantl ausgefuehrtenuntersuch ungen uber die 

 Anatomine Ulmaceen. Bot. Centralblatt, Vol. L, p. 105. 



*Recherches anatomiques sur le genere Carex (Eevue generale de Botanique, Vol. 

 Ill, 1391, p. 57-64. Abst. Bot. Centralblatt, Vol. LI, p. 116. 



5 Uber den systematischen Werth den Holzstructur bei den Dicotyledonen. R. 

 Oldenbourg, Muencben. 1885. 



6 Beitraege zur AnatomiederSaxifragaceen und deren Systematische Verwerthung. 

 Bot. Centralblatt Vol. LIII. p. 33, 65, 97, 139, 161, 209. 



7 Beitraege der vergleicbenden Anatomie der Saxifragaceen. Bot. Centralblatt Vol. 

 XLIII. p. 100, 136, 161, 233, 281, 313, 315, 377. 



?Beltraege zur vergleicbenden Anatomie des Stengels der Caryopbylleenund Saxi- 

 frageen. Diss. Marburg, 1887. 



8 Sur l'appareil de soutien dans les tiges des Saxifrages. 



9 Die Kaldruesen der Saxifrageen. Graz 1887. 



10 Monographie der Gattung Saxifraga. Breslau 1872. 



Synopsis of North American Pines, based on leaf-anatomy. Bot. Gazette, XI, p. 

 256, 302; plate VIII. 



Die Anatomie der Euphorbiaceen in ihrer Beziebung zum system derselben. Sepa- 

 rate Engler's Botamische Jahabucher, Vol. V, p. 384-421; plates VI and VII. 



