1918] DUDGEON—RUMEX CRISPUS 417 
sterility in the grape is only a step toward functional dicliny.”’ 
All the scanty published evidence I have seen seems to support this 
conclusion. 
Summary 
1. Organogeny is normal, with slight delay in appearance of 
petals and carpels. 
2. The megaspore mother cell produces a tetrad of megaspores, 
the innermost of which functions. The haploid chromosome 
number is 32. 
3. The embryo sac is of the ordinary 8-nucleate type. 
4. Microsporogenous tissue is formed from the primary sporoge- 
nous cell by 3-4 successive divisions, and reduction is normal. 
The haploid chromosome number is 32. 
5. The mature pollen grain contains two male nuclei, the 
progeny of a definite generative cell. 
6. There is good negative evidence both for and against the 
occurrence of fertilization. This raises the question whether some 
of the megaspore mother cells may not undergo reduction, while 
others only simulate reduction and give rise to a diploid embryo 
sac, the latter only producing embryos by the apogamous develop- 
ment of the egg. 
7. Widespread degenerations occur: (a) in any or all of the 
anthers, at any stage from the sporogenous initial to the mature 
pollen grain, and may involve only the sporogenous tissue and its 
products, or the entire anther; (0) in the ovary, at any stage from 
the functioning megaspore to the maturing fruit, and may involve 
only the embryo sac, or both embryo sac and ovule, or the entire 
ovary; (c) in entire inflorescences. 
8. Most pollen grains undergo cytolysis, with abundant starch 
formation, conspicuous enlargement, and the formation of “pollen 
tubes.”’ 
g. Only a small percentage of pollen grains and embryo sacs have 
the appearance of being functional. 
ro. An unidentified fungus invades the anthers after dehiscence, 
ramifying among but rarely penetrating the pollen grains. 
11. There is a definite abscission layer near the base of the 
peduncle, cutting off either before or after blooming those flowers 
