RECORD: Darwin, C. R. [1866].10.14-1868.06.24. Sweet pea [comparison of crossed and self-fertile plants in height]. CUL-DAR78.133-137. Edited by John van Wyhe (Darwin Online, http://darwin-online.org.uk/)

REVISION HISTORY: Transcribed by Christine Chua and edited by John van Wyhe 2.2023. RN1

NOTE: See record in the Darwin Online manuscript catalogue, enter its Identifier here. Reproduced with permission of the Syndics of Cambridge University Library and William Huxley Darwin.


(18

Oct 14th Planted the 4 other crossed peas.; not 2 rotted, & not till 24th 7° 30' A.m one germinated, after all the uncrossed other uncrossed had germinated; planted it. About 45° subsequently (ie say on Oct 26th 5 7° A.m) 2 uncrossed peas of other lot germinated & were planted so 45° younger. — say 48° younger. —

(Oct 30th 7° 30' A.m a second crossed pea marked by bit of zinc (ie 4 days after the 2 uncrossed.) germ. & planted, & 24° subsequently one uncrossed one germ. & planted; (this second uncrossed killed by Slugs) both marked by bits of Zinc.)

Nov. 5th First crossed pea 3 1/2 inches high to tip of leaflets; & 48˚ afterwards the tallest of the two self-fert. peas was only nearly 3/4 of inch shorter. —

Remember that crossed peas was unwholesome. —

(Nov. 13th Second crossed pea nearly 2.7 high, & the tallest of the 2 uncrossed peas (4 days previously ie at same age) was .6 of inch taller; so uncrossed has advantage.)

(Feb. 10th The crossed pea marked with zinc which is 4 days younger than the uncrossed self-fertilised peas now equal those in height—

The other crossed peas was which had germ 48 before the self was taller than the self-fertilised was bitten off by slug, so case for present spoiled. —

But both crossed pea look more vigorous & have larger leaves than the 2 self-fertilised plants.) /over

[18v]

March 31' The crossed pea with zinc & youngest is now 3 ft ..7 in high, & the other crossed plant of which tip was bitten of is 3 ft .. 5 in high; whereas the w self-fertilised plants are only 3 ft .. 1 1/2in high— so quite conquered.)

(May 1'. The crossed Pea of which tip was bitten off is now at top of stake & 6 ft .. 8 inch — the other crossed pea is 6 ft. 5 in — average 6. 6 1/2 — The tallest of the self-fert. pea is only 5. 4. 1/2 — & 5 ft 3 in

Reduce & call stake 6 ft high. so

(6 ft. 6 in 1/2: 6: : 5. 4 1/2: x = 4 ft. 11 inches) when crossed were 6 ft high, the self-fert. was only 4 ft. 11 in

(May 12. These plants are now in flower: the self-fert. are of crossed course "painted Ladies": the 2 crossed plants, though produced from "painted Lady" have taken after their father & are purple like the "Purple"; but I think not quite so dark & with keel-patch a little streaked.

I have crossed the 2 crossed plants; 6 fl. white Thread. — These 2 crossed & 2 self-fert. all grown in same pot.

(18A

Sweet Pea. 1867 in greenhouse.

Two plants, descended from Painted Lady & Purple crossed, had some 6 flowers crossed, & produced 6 pods, with average of 6.0 (Max 7. Min 5) peas per pod— which 36 peas weighed 51.12 gr. Therefore 46 Peas would have weighed 65.32 gr.

Ten pods spont. self-fert. under net on these crossed plants were saved & they contained on average 4.6 peas per pod (with max. of 6 & min of 3) & these 46 peas weighed 62.77 gr.

So crossed peas more numerous & rather heavier.

(A painted Lady raised from self-fert. seed, spont. self-fertilised itself & 19 18 pods contained on average 3.79 3.93 seed with max of 5 & minimum of 2. The peas were fine for 46 weighed 65.85 gr. —owing, perhaps to be their being few — Perhaps give only average number.

(Feb. 29 many of the self-fertilised seeds of both sorts have certainly germinated sooner than the crossed seeds.)

[18Av]

July 8 68/ Some crossed & self-fert. sweet Peas were sown in Box with Brugmansia, where the convolvulus wd not grow, but these grew well. — The tallest plants measured, — (These Peas belong to lots measured on p. 18 C.

In Greenhouse

 

 

July 8'

 

Aug 23'

Crossed

ft in

6 — 5 1/2

5 — 8 1/2 inches

9 0 1/2

Selfs

ft  inches

6 — 5 1/2

7. 11.

 

Produced 7 Pods

Produced 9 Pods

 

The self flowered first, & have always until last measurement on Aug. 25 beaten crossed Some of same 2 lots were sown out of doors in poor soil in Shrubbery & grow very dwarf owing to very hot summer & the crossed were beaten by self from Painted Lady & by selfs from crossed, but then growth completed (Aug 23d)

The tallest crossed was 30 inches high

The tallest self was 29. 3/8 high.

84 [+] 11 [=] 95

(18B

Sweet Pea 2d generation

(April. 3d 1868. In none of the several Pots, any great difference in Plants; now 4-6 inches high.)

June 1868 in Pot I & 2 crossed flowered first — in another Pot flowered at same time). (Pot IV. self- flowered first)

(June 24th The plants have now come to full growth.

Pot 3. Three crossed Plants

 

6. 0 1/2 feet

Pot I 5 11

4. 4 1/4} produced 16 pods

Three self- plants from Painted Lady, no doubt self-fertilised Plant

4. feet 9 1/2

5. 7

4. 8 1/4} produced 19 pods so more fertile!

16. 3 3/4

15. —3/4

In another Pot the crossed was ahead of two self plants, but wind broke down the shoot & injured it & is now greatly beaten. — In another Pot, the crossed plant was eaten in twain by caterpillar, when this occurred it was 5 ft. 10 in high, whilst a self-plant from a crossed plant was 6.2 inches high & so crossed was beaten by the self-plant, but it was was higher 1 ft 5 in higher than a self from painted Lady in same Pot.)

Pot IV. Three crossed Plants

Pot II 6 feet 9 1/2

3 9 1/4 produced 19 Pods [+] 16 [=] 35

4. 7

Three self- plant

5 feet 6 1/4

3 2 7/8 produced 13 pods [+] 19 [=] 32

3 10

add up Pots 3 & 4 together — 31. 5 1/2

27 7 7/8

 

18B

[calculations not transcribed]

[18Bv]

The p two lots are the grandchildren of the P. L., on one side twice crossed for 2 generations, & on the other side self-fertilise from A. probably for many generations.

[calculations not transcribed]

(18C

Sweet Pea. continued. I germinated at same time seed from Painted Lady plant, (which general consideration make me suppose long self-fertilised) & seed from a plant which had been crossed, by me viz Painted Lady & Purple. — Both sets of seeds were spont. self-fert. & were treated most fairly & sown in pairs on opposite sides & sown in 4 Pots. Their height when full grown were as follows.

[table not transcribed]

see Back of p. 18 A Table 55


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Citation: John van Wyhe, ed. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)

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