6o KANDA— VERBENA 1920 



9. Hegelmaier, F. , Untersuchungen liber die Morphologie des Dikotyledonen- 

 Endosperms. Nova Acta Leopoldina 49:1-104. pis. 5. 1885; rev. Bot. 

 Centralbl. 25:302-304. 1886. 



10. Hofmeister, W., Neuere Beobachtungen iiber Embryobildung der Phane- 

 rogamen. Jahrb. Wiss. Bot. 1:82-188. pis. 7-10. 1858. 



11. Ishiwaka, M., Studies on the embryo sac and fertilization in Oenothera. 

 Ann. Botany 32:297-317. pi. 7. figs. 14. 1918. 



12. Lloyd, F. E., The comparative embryology of the Rubiaceae. Mem. 

 Torr. Bot. Club 8:27-112. pis. 8-15. 1902. 



13. Merrell, W. D., A contribution to the life history of Silphium. Bot. 

 Gaz. 29:99-133. pis. 3-10. 1900. 



14. Mottier, D. M., On the development of the embryo sac of Arisaema 

 Iriphyllum. Bot. Gaz. 17:258-260. pi. 18. 1892. 



15. Murbeck, S., Uber die Embryologie von Ruppia rostellata Koch. Handl. 

 Svensk. Vetensk. Akad. 36:21. pis. 3. 1902. 



16. Rosenberg, O., Cytologische und morphologische Studien an Drosera- 

 longifoliaXrotundi folia. Handl. Svensk. Vetensk. Akad. 43:1-65. pis. 4. 



figs- 33- 1900- 



17. Schaffner, J. H., Contribution to the life history of Sagittaria variabilis. 



Bot. Gaz. 23:252-273. pis. 20-26. 1897. 



18. Webb, J. E., A morphological study of the flower and embryo of Spiraea. 

 Bot. Gaz. 33:451-460. figs. 28. 1902. 



EXPLANATION OF PLATES YI-IX 



Figs. 10-17, 27, 54-63, 69-75 are in the text; all the others in the plates. 

 All drawings were made with an Abbe camera lucida at table level. Figs. 11- 

 17, 27, and 60-63 were drawn with Zeiss compensating ocular no. 4 and Spencer 

 16 mm. objective; figs. 18-25, 28-41, and 64-68 with Reichert ocular no. 18 

 and Spencer 4 mm. objective; figs. 26 and 42-53 wltri Zeiss compensating 

 ocular no. 4 and Bausch and Lomb 1/12 oil immersion objective; figs. 69-75 

 with Reichert ocular no. 18 and Bausch and Lomb 1/12 oil immersion objec- 

 tive. Text figures reduced one-half, plates nearly two-thirds in reproduction. 

 The original magnification will be specified for each figure in the plates. 



PLATE VI 



All figures reduced five-twelfths. 



Fig. 1. — Verbena angiistifolia Michx. 



Fig. 2. — Taxonomically intermediate form between I*. angiistifolia 

 Michx. and V. stricta Vent. 



Fig. 3. — V. stricta Vent. 



Figs. 4-6— Taxonomically intermediate forms between V. stricta Vent, 

 and V . hastata L. 



Fig. 7. — V . hastata L. 



Figs. 8, 9. — Taxonomically intermediate forms between V. hastata L. and 

 V. angiistifolia Michx. 



