172 
The Ohio Naturalist. 
[Vol. IV, No. 8, 
and “first leaf” of Xelumbo and the similar structures of the 
Araceae mentioned above. A careful study of all the Helobiae 
with “ macropodous ” embr 3 ’os, as well as other monocotyledon- 
ous tj’pes, will probably be necessary before a definite conclusion 
can be reached. 
RECENT LITERATURE. 
Lyon, H. L. Observations on the Phnbryogeny of Xelumbo. Minn. Rot. 
Studies. 2 ; 643-655. 1901. 
Cook, M. T. Development of the Embryo-sac and Embryo of Cast.nlia 
odorata and Xymphaea advena. Bull. Torr. Rot. Club. 24 :2ii- 
220. 1902. 
MurbECK, Sv. Ueber die Embryologie von Ruppia Rostellata Koch. 
Kongl. Svenska Vetenskapa-Akademiens Ilandlingar. Baiidet 
36. Xo. 5. 1902. 
Campbell, D. H. Notes on the Structure of the Embryo-sac in Spargani- 
um and Lysichiton. Rot. Gaz. 27 ; 153-166. 1S99. 
Campbell, D. PI. Studies on the Araceae. Ann. Rot. 14 : 1-25. 1900. 
ScHAFFNER, J. H. Some Morphological Peculiarities of the Nymphaeaceae 
and Helobiae. Ohio Xat. 4 ; 83-92. 1904. 
EXPLANATION OF PLATES. 
The figures were drawn with the aid of an Abbe camera and the following 
combination of oculars and objectives: P'igs. 2-7, 9-13, 20, 22, 23, 25 and 26, 
Rausch & Lomb j’j obj., Leitz oc. 4 ; Figs. 15, 28-32 and 34, Leitz 1 obj. and 
oc. 4 ; Figs. 14, 16-19 ami 33, Leitz } obj. and oc. 2 ; P'igs. 21, 24 and 27, 
Rausch & Lomb obj. and oc. 2. 
Fig. I. 
Fig. 2. 
Fig. 3- 
Fig. 4. 
F'ig. 5- 
Fig. 6. 
Fig. 7- 
Fig. 8. 
Fig. 9. 
Fig. 10. 
Fig. II. 
Fig. 12, 
Fig. 13. 
PLATE XVI. 
Young carpel before the integuments appear on the ovule. 
Xucellus with archesporial cell. 
The megasporocj’te and primary j^arietal cells. 
Megasporocyte and three parietal cell. 
Megasporocyte and twelve parietal cells, six of which show in one 
plane. 
The four megaspores, the lowest enlarging as the functional mega- 
spore. 
The nucellus with cap of tissue developed from the epidermis. 
Carpel with two celled embryo-sac in the ovule, showing the stylar 
canal lined with glandular cells. 
Two-celled embryo-sac with remains of the three potential mega- 
spores. 
P'our-celled embryo-sac. 
Eight-celled embryo-sac, showing conjugation of the polar nuclei 
and disorganization of the antipodals. 
Upper end of embryo-sac, showing the oosphere, synergids and 
conjugating polar nuclei. 
Upper end of embryo-sac, showing tripple fusion, the egg, remains 
of pollen tube, and synergid. 
