2*.tS Beer, Development of tlic polleii graiii and anllior of some Oiiaj;riu-cae. 



^2. Absolute Alcohol. 



Pollen «rrain = G2 



/'^ 



„ cavity = not measured, 

 „ protoplast =16 //. 

 Alcohol always cansed fjjroat slirinkage of tho protoplast. 



VI. The folU»\vin<i; ohscrvations were uiade upun tlie pollen 

 grain.'^ in the following media. 



1. The stamen was placed in a drop of olive oil and 

 the pollen carefuUy teased ont without coniing into 

 contact Avith the air. 



Pollen grain = 68 ii. 



„ cavity = 41 ,(/, 

 „ protoplast = 28 //. 



2. Pollen grains teased rapidly into distilled water and 

 inimediatly exaniined showed a protoplast of 28 // in 

 pollen grain 68 // across; very soon however the 

 vacuoles of the proto])last enlarged, rnptured the 

 separating arms and laminae of cytoplasm and ran 

 together so that the protoplast slow^y swelled up 

 until it qnite hlled the pollen-cavity (42 //l 



3. In 2% cane sngar the results were similar to those 

 in distilled water. 



4. In 5% cane sugar. 



The protoplast for some time maintained its size 

 28 to 30 //. Later, however in some of the pollen 

 OTains changes similar to those of 2. and 3. were 

 Seen but mucli less marked. 



5. In 0,6VoNaCl. 



The protoplast measnred about 28 ii and it remained 

 unaltered after a prolonged examination. 



6. In 2 o/o Na Cl. 



Protoplast measured only 20 ^i and was obviously 

 plasmolysed. 

 The following observations upon 0. hiennis may also be 

 mentioned. 



I carefuUy and as rapidly as possible teased out the jDoUen 

 grains into a little of the mucilaginous fluid which can be squee- 

 zed from the anther itself. In a pollen grain measuring 68 (i 

 and with a cavity of about 40 ^i the protoplast measured 30 ,«. 

 I then added a drop of 0,6 Vo Na Cl Solution to the above, 

 watching the effect all the time. The pollen grains remained 

 unchanged both in their appearance and in theh' measure- 

 ments. 



In another similar experiment upon another bud from a 

 different plant the measm^ement both in the anther-juice and in 

 the 0,6 °/o Na Cl Solution were : 



Pollen grain = 74 (i^ 



„ cavity = 40 //, 

 „ protoplast = 30 fi. 



