88 NOTICES OF BOOKS. 
crowded sowings, where there was a great struggle for or. only 
the tallest of the full-grown survivors were measured. thod 
tion to be underrated, and the same remark would apply to the mood 
source of error. 
It will be convenient to take Jpomea purpurea as a Pe 2 and to 
exhibit the main results obtained from this species in two 
Ipomea purpurea. Summary of Measurements {in Inches) of the ten 
Generations. 
Py a 73 
Number of | Number} Average | Number @ 8 5.2 i 
of height of | ofself- | height of E Sans 
generations. | crossed| crossed | fertilised | self-ferti- | 8 2 os a 
plants. | _ plants. plants. /lised plants.! “o ¢ 5.5 
eos 
as 
| First generation 6 86-00 6 65°66 as 100 to 76 
Second generation 6 84°16 6 66°33 as 100 to 79 
Third generation 6 77-41 6 52°83 | as 100 to 68 
| Fourth generation 7 69°78 7 60:14 | as 100 to 86 
| Fifth generation 6 82:54 6 62°33 | as 100 to 75 
Sixth generation 6 87°50 6 63°16 | as 100 to 72 
Seventh generatn.| 9 83-94 9 68:25 | as 100 to 81 
Eighth generation! 8 113°25 8 96°65 | as 100 to 85 
Ninth generation 14 81°39 14 6407 as 100 to 79 
Tenth generation | § 93-70 5 50°40 | as 100 to 54 
All the ten gene- | 
rations taken 
together. Ge 85°84 | 73 - 66°02 | as 100 to 77 
