1915] MICHELL—STRIGA LUTEA 133 
BERNARD (2) was led to the same conclusion from a study of 
four total parasites: Lathraea, Orobanche, Phelipaea, and Cytinus, 
in which he found that all stages of haustorial development were 
represented. Lathraea shows the most extensive haustorial devel- 
opment of the four genera, while in Cytinus the endosperm is 
normal or nearly so. 
In the production of fertile seeds the parasitic members of the 
family seem not one degree less successful than their independent 
relatives, and there is nothing in the history of the ovule of parasites 
to lead one to suppose that it has suffered orang to the mode of 
life adopted by the parent plant. 
Summary 
1. Striga lutea is a semi-parasitic annual belonging to the 
Rhinantheae-Gerardieae group of the Scrophulariaceae. 
2. The ovary is of the ordinary bilocular scrophulariaceous 
type, and the ovules are anatropous, with one integument. 
3. The megaspore mother cell arises directly from a single sub- 
epidermal cell, which gives rise to a row of four ees: of 
which the lowest develops into the embryo sac. 
4. The 8-nucleate embryo sac develops in the normal way, and 
at the time of fertilization contains two synergids, an egg, the fused 
polar nuclei, which lie in the upper part of the sac, and three antip- 
odal cells, which show signs of disintegrating. 
5. Double fertilization occurs. 
6. Endosperm is formed by cell division. From the chalazal 
end a long binucleate haustorium is formed, penetrating the integu- 
ment. The micropylar haustorium is inconspicuous, simply 
consisting of a few ordinary endosperm cells with fairly dense 
contents, 
7 lhe proembryo has a long suspensor of three or four cells. 
The basal cell of the suspensor forms tuberous haustoria. 
8. The mature embryo is of the usual dicotyledonous type and 
is surrounded by one thick-walled layer of endosperm cells. 
9. The testa consists of one layer of lignified cells which are 
admirably suited to protect the young embryo. 
