Plantago LaiiccolatLi Ruinosa. 159 



comparison. At the l)eginning of the period of flowering 

 no difference was discernil^le in either experiment be- 

 tween the two halves, but it gracktally became visible 

 during the course of the summer. I picked off all the 

 ears from the culture in sand at the end of July and at 

 the end of August ; here is a record of them : 



Number of lateral ears per primary ear Totals 

 12 3 4 5 



July 28th ^^^^^-^ 3 3 4 6 3 1 



20 



/ Control 9 7 9 6 31 



48 



Aug. 31st -i^^^"^^ 14 10 12 8 3 1 



i Control 12 2 10 7 6 2 39 



The difference though slight is distinct. It is more 

 clearly l)rought out if the mean number of lateral ears 

 per primary ear is calculated. In August in the plants 

 on sand this was 1.5, in the control half 2. 



A similar effect was produced by shade which exerted 

 a most deleterious effect on the whole growth of my 

 experimental plants as will be seen from the small number 

 of ears produced. I obtained the following figures in 

 the same way as in the previous experiment. 



Number of lateral ears per primary'- ear Totals 

 1 2 3 4 S 6 



July 28th -i^^hade 7 6 2 7 5 2 29 



i Control 1 1 2 8 19 20 1 52 



Ausr 31st -^ ^^^^^^ 15 1 1 2 19 



( Control 21 9 20 16 10 3 79 



The mean numl)er of subsidiary ears per primary 

 ear in August in the shadow half was 0.5 and in the 

 control half 2.0. 



In conclusion, the results of the whole series of ex- 

 periments which has lasted over more than ten years 

 may be summarized as follows : The Plantago lancrolafa 

 ramosa of ]iiy experiment constitutes an '^inconstanf 



