BIO Eei'ort of the Horticultural Department of the 



70° F. or slightly more. At 9.30 a. m. of the following day per- 

 haps half of the grains in No. 9 had germinated but they showed 

 decidedly the retarding effect of the poisons. In No. 10 the ger- 

 mination and growth were no better than in No. 9, really not 

 quite so good. In No. 11 the grains germinated freely; nearly 

 or quite all of them had germinated andlhe tubes had made free 

 growth. In No. 12 germination and growth had progressed as 

 freely as in No. 11. 



At 5.20 p. m. of the same day, about 24 honrs alter the cul- 

 tures had been started, these notes were made. 



No. 9. Pollen tubes vary from 1.96/^. to 18.48' long; average 

 length perhaps 10/^. Many tubes which were apparently in per- 

 fect condition this morning have now broken down and 

 become disintegrated. Many of the pollen grains have not yet 

 germinated. 



No. 10. Pollen tubes vary from 1.68,a to 14,^. long. They 

 average perhaps 7m. Some of the pollen tubes have become dis- 

 integrated like those noted in No. 9. 



No. 11. The pollen tubes have made good growth. They 

 vary in length from 10.67/^ to 87.36At and average perhaps from 

 60,v- to 75 '. Occasionally tubes are seen which are abnormally 

 swollen and give some appearance of breaking down. 



No. 12. The pollen tnbes have made good growth. The tubes 

 vary in length from 8.4a to 75.6/a or more. No disintegration of 

 pollen tubes was noticed. 



At 5 p. m.. May 22, four days after these cultures were made, 

 the following notes were taken and the cultures were then 

 discarded. 



No. 9. It is estimated that from 30 per ct. to 50 per ct. of the 

 pollen grains in this culture have germinated. One of the 

 longest tubes measured 51.96/^, but such length was quite excep- 

 tional. Most of the tubes were less than one-half or even one- 

 third of that length; many were no longer than from 5// to 10,a 

 The tubes are apt to be abnormally curved or twisted and the 

 growth is not vigorous. Indeed there is an appearance of dis- 

 integration of some of tlie tubes. 



