- 



514 BOTANICAL GAZETTE [December 



to Professor B. M. Duggar for helpful suggestions during that part 

 of the investigation which was conducted at Wood's Hole. 



Wellesley College 



THE DISTRIBUTION OF DL\PHRAGMS IN THE VARIOUS GROUPS OF PLANTS 



i. Pteridophytes. — They are reported for ferns and Equisetum by 

 Leitgeb (18), but are not mentioned by Costantin (3) in his report on 

 Equisetum. 



2. Spermatophytes. — 



a) No mention has been made of the presence of diaphragms in the gymno- 



sperms. 



b) Diaphragms have been observed in the following families of angio- 



sperms: 



(1) Dicotyledons: 



In Nymphaeaceae by Leitgeb (18), Solereder (31), and Le Blanc (17). 

 Their presence in Nelumbium (Nelumbo) is denied by DeBary (6). 



In Ceratophyllaceae by Duval- Jouve (7) , but their presence is denied by 

 Meyen (20, 21), DeBary (6), and Schenck (29). 



In Haloragidaceae by Leitgeb (18) and Goebel (13), but their pres- 

 ence is denied by Meyen (20, 21), Duval- Jouve (7), DeBary (6), and 

 Schenck (29). 



In Gentianaceae by Duval-Jouve (9), but their presence in Limnan- 

 themum nymphoides is denied by DeBary (6). 



In Rubiaceae by Unger (35) for Richardia aethiopica (authority not 

 noted). In Engler and Prantl Richardsonia is given as a synonym for 

 Richardia, but the species aethiopica does not appear, and it is not safe to con- 

 clude from this report that diaphragms occur in this family. 



In Umbelliferae by Leitgeb (18) and (at nodes) by CourchetU), but 

 their presence is denied by Meyen (20). 



In Compositae by Leitgeb (18). 



Costantin (3) made an extended study of water plants, including many 

 families, the greater number of which were dicotyledons, but he does not 

 mention the presence of diaphragms. Le Blanc (17) states that they occur 

 only in monocotyledons and the related Nymphaeaceae. 



(2) Monocotyledons: 



In Typhaceae by Leitgeb (18), Duval-Jouve (7, 9), and Falkenberg 



(12). 



In Pandanaceae by Meyen (20). 



In Sparganiaceae by Duval-Jouve (7, 9). 



In Potamogetonaceae by Duval-Jouve (9), Sauvageau (25, 26, 27), 

 and Meyen (21). Their presence is denied in Zoster a and Posidonia caidini 

 by DeBary (6). Sauvageau (25) reports them for Zostera, but does not 

 consider the thin partitions extending from epidermis to epidermis in the 



