172 



The Ohio Naturalist. 



[Vol. IV, No. 8, 



and "first leaf" of Nelumbo and the similar structures of the 

 Araceae mentioned above. A careful study of all the Helobiae 

 with " macropodous " embryos, as well as other monocotyledon- 

 ous types, will probably be necessary before a definite conclusion 

 can be reached. 



RECEJNT LITERATURE. 



Lyon, H. I,. Observations on the Embryogeny of Nelumbo. Minn. Bot. 

 Studies. 2:643-655. 1901. 



CoOK, M. T. Development of the Embryo-sac and Embryo of Castnlia 

 odorata and Nymphaea advena. Bull. Torr. Bot. Club. 24 : 211- 

 220. 1902. 



Murbj:ck, Sv. Ueber die Embryologie von Ruppia Rostellata Koch. 

 Kongl. Svenska Vetenskapa-Akademiens Handlingar. Bandet 

 36. No. 5. 1902. 



Campbei,Iv, D. H. Notes on the Structure of the Embryo-sac in Spargani- 

 um and Lysichiton. Bot. Gaz. 27 : 153-166. 1S99. 



Campbeli^, D. H. Studies on the Araceae. Ann. Bot. 14 : 1-25. 1900. 



SCHAFFNER, J. H. Some Morphological Peculiarities of the Nymphaeaceae 

 and Helobiae. Ohio Nat. 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: Figs. 2-7, 9-13, 20, 22, 23, 25 and 26, 

 Bausch & Lomb yV obj., Leitz oc. 4 ; Figs. 15, 2S-32 and 34, Leitz 1 obj. and 

 oc. 4 ; Figs. 14, 16-19 ^"d 33i Leitz \ obj. and oc. 2 ; Figs. 21, 24 and 27, 

 Bausch & Lomb ^^ ohj. and oc. 2. 



PLATE XVI. 



Fig. I. Young carpel before the integuments appear on the ovule. 



Fig. 2. Nucellus with archesporial cell. 



Fig. 3. The megasporocyte and primary parietal cells. 



Fig. 4. Megasporocyte and three parietal cell. 



I'ig. 5. ^Megasporocyte and twelve parietal cells, six of which show in one 

 plane. 



Fig. 6. The four megaspores, the lowest enlarging as the functional mega- 

 spore. 



Fig. 7. The nucellus with cap of tissue developed from the epidermis. 



Fig. 8. Carpel with two celled embryo-sac in the ovule, showing the stylar 

 canal lined with glandular cells. 



Fig. 9. Two-celled em])ryo-sac with remains of the three potential mega- 

 spores. 



Fig. 10. Four-celled embryo-sac. 



I'ig. II. Eight-celled embryo-sac, showing conjugation of the polar nuclei 

 and disorganization of the antijjodals. 



F'ig. 12, Upper end of embryo-sac, showing the oosphere, synergids and 

 conjugating polar nuclei. 



Fig. 13. Upper end of embryo-sac, showing tripple fusion, the egg, remains 

 of pollen tube, and synergid. 



