“Self-fertilization Induced by Artificial Means.” (1904)

Finally, Thomas Hunt Morgan’s work with the ascidian Ciona intestinalis, which is a vase tunicate that goes by the common name “sea squirt,” illustrates his eclectic curiosity. Why is this case curious? Well, Morgan first publishes about Ciona intestinalis in 1904. He also picks this line of work up again almost 20 years later (in 1923) after several years of publishing almost exclusively about the fruit fly. For the sea squirts, Morgan wanted to know how these tiny vase-shaped hermaphroditic marine invertebrates prevented self-fertilization. William Castle had discovered through experiment that in sea squirts the sperm would not fertilize the eggs if the sperm came from the same individual. The sperm of one individual, however, could fertilize the eggs of another individual without problem. So, Morgan wanted to know what process allowed these vase-tunicates to prevent self-fertilization. One way he proposed to find out: by attempting to trick the sea squirts into fertilizing its own eggs.

Prior to this work, Morgan had been thinking a lot about regeneration and “polarity,” or the observation that the organism somehow knows which part to regenerate when it is injured or damaged. The prevention of self-fertilization in sea squirts involves a similar notion that the organism somehow knows not to fertilize itself. Similar to some of his previous experimental work, he hoped to find out about the normal process of fertilization by stimulating it in an organism that had a peculiar capacity to prevent fertilization from occurring under certain circumstances:

My object in undertaking a study of this problem was, in the first place, to determine if possible the nature of the conditions that prevent or interfere with self-fertilization; and in the second place, I was not without hope of being able to find some way in which self-fertilization could be artificially induced.

More than simply experiment, this work shows Morgan reasoning through all of the possible circumstances by which embryological development does not begin in the case of sea squirts. Does it secrete a substance that enhances the ability of sperm to fertilize, or does it secrete a substance that restricts it? What if the sperm are actually making it into the egg, but development still isn’t beginning? How might one devise an experiment to substantiate one hypothesis and rule out other competing hypotheses? This is also—like Morgan’s work with echinoderm crosses—a replication experiment, in which Morgan does similar work as a contemporary scientist and either affirms or refutes their conclusions. In this case, Morgan refuted William Castle’s theory that attempted to account for the determination of sex, stating that his observations do not support Castle’s assumptions.

Thomas Hunt Morgan’s work shows that his method was to induce abnormal conditions experimentally in order to pin down exactly what normal processes were occurring. His work with a variety of different organisms was more typical of his behavior and method as a working scientist in his early years, than his later work with fruit flies.

Suggested citation
Cohmer, Sean. 2017. "Using Biodiversity." MBL History Project digital exhibit. http://history.archives.mbl.edu/exploring/exhibits/using-biodiversity
Bibliography

Survey and Collecting

Report Upon the Invertebrate Animals on Vineyard Sound and Adjacent Waters

  •  Verrill, Addison Emery and Sidney Irving Smith. Report Upon the Invertebrate Animals on Vineyard Sound and Adjacent Waters. 1873.
  •  -- A biological survey of the waters of Woods Hole and vicinity
  •  Sumner, Francis B. "The Biological Laboratory of the Bureau of Fisheries at Woods Hole, Mass. Report of Work for the Summer of 1904." (1905): 566-572.
  •  Sumner, Francis Bertody, Raymond Carroll Osburn, Leon Jacob Cole, and Bradley Moore Davis. A biological survey of the waters of Woods Hole and vicinity. Vol. 31. Govt. Print. Off., 1913.
  •  -- Methods for obtaining and handling marine eggs and embryos
  •  Costello, Donald P., and Catherine Henley. Methods for obtaining and handling marine eggs and embryos. Marine Biological Laboratory, 1957.

Experiment

  •  Morgan, Thomas Hunt. “Experimental studies on echinoderm eggs.” Anat. Anz. 9 (1893): 141–52.
  •  Morgan, Thomas Hunt. "A Study of Metamerism." Quarterly Journal of Microscopical Science 37 (1895): 395.

On Regeneration

  • Morgan, Thomas Hunt. "An Analysis of the Phenomena of Organic 'Polarity'." Science 20 (1904): 742–8.
  • ———. "An Attempt to Analyze the Phenomena of Polarity in Tubularia." Jour. Exp. Zool. 1 (1904): 587–91.
  • ———. "Experimental Studies of the Internal Factors of Regeneration in the Earthworm." Arch. Entw.-Mech. 14 (1902): 562–91.
  • ———. "Experimental Studies of the Regeneration of Planaria Maculata." Arch. Entw.-Mech. 7 (1898): 364–97.
  • ———. "The Factors That Determine Regeneration in Antennularia." Biol. Bull. 2 (1901): 301–5.
  • ———. "Further Experiments on the Regeneration of the Appendages of the Hermit-Crab." Anat. Anz. 17 (1900): 1–9.
  • ———. "Further Experiments on the Regeneration of the Tail of Fishes." Arch. Entw.-Mech. 14 (1902): 539–61.
  • ———. "Further Experiments on the Regeneration of Tissue Composed of Parts of Two Species." Biol. Bull. 2 (1900): 111–9.
  • ———. "Further Experiments on the Regeneration of Tubularia." Arch. Entw.-Mech. 13 (1902): 528–44.
  • ———. "Growth and Regeneration in Planaria Lugubris." Arch. Entw.-Mech. 13 (1901): 179–212.
  • ———. "The Internal Factors in the Regeneration of the Tail of the Tadpole. (with S. E. Davis)." Arch. Entw.-Mech. 15 (1902): 562–91.
  • ———. "Notes on Regeneration." Biol. Bull. 6 (1904): 159–72.
  • ———. Regeneration. Biology Series.  New York: Columbia Univ., 1901.
  • ———. "Regeneration and Liability to Injury." Zool. Bull. 1 (1898): 287–300.
  • ———. "Regeneration and Liability to Injury." Science 14 (1901): 235–48.
  • ———. "Regeneration in Allolobophora Foetida." Arch. Entw.-Mech. 5 (1897): 570–86.
  • ———. "Regeneration in Bipalium." Arch. Entw.-Mech. 9 (1900): 563–86.
  • ———. "Regeneration in Planarians." Arch. Entw.-Mech. 10 (1900): 58–119.
  • ———. "Regeneration in Teleosts." Arch. Entw.-Mech. 10 (1900): 120–34.
  • ———. "Regeneration in the Egg, Embryo, and Adult." Am. Nat. 35 (1901): 949–73.
  • ———. "Regeneration in the Hydromedusa, Gonionemus Vertens.". Am. Nat. 33 (1899): 939–51.
  • ———. "Regeneration in Tubularia." Arch. Entw.-Mech. 11 (1901): 346–81.
  • ———. "Regeneration of Proportionate Structures in Stentor." Biol. Bull. 2 (1901): 311–28.
  • ———. "Regeneration of the Appendages of the Hermit-Crab and Crayfish." Anat. Anz. 20 (1902): 598–605.
  • ———. "Regeneration of the Heteromorphic Tails in Posterior Pieces of Planaria Simplicissima." Jour. Exp. Zool. 1, no. 385–91 (1904).
  • ———. "Regeneration of the Leg of Amphiuma Means." Biol. Bull. 5 (1903): 293–6.
  • ———. "Regeneration of Tissue Composed of Parts of Two Species." Biol. Bull. 1 (1899): 7–14.
  • ———. "Regeneration: Old and New Interpretations." Biol. Lect., Woods Hole, 12th  (1900): 185–208.
  • ———. "Some Factors in the Regeneration of Tubularia." Arch. Entw.-Mech. 16 (1903): 125–54.
  • ———. "Some Problems of Regeneration." Biological Lectures, Woods Hole  (1898): 193–207.
  •  Morgan, Thomas Hunt. "Self-fertilization induced by artificial means." J Exp Zool 1 (1904): 135-178.

Supply and SaleSupply

  • “The Marine Biological Laboratory, Ninth Report for the Years 1896–1899 and Statistics of the Years 1900–1902.” The Biological Bulletin (1902): 173.
  • “The Marine Biological Laboratory, Thirty-Third Report for the Year 1930—Forty-Third Year.” The Biological Bulletin 61 (1931): 13.

Sale

  • Pauly, Phil. Biologists and the Promise of American Life: From Meriwether Lewis to Alfred Kinsey. (Princeton U. Press, 2000): 187.
  • Lipshitz, Howard. “From Fruit Flies to Fallout: Ed Lewis and His Science.” Developmental Dynamics 232 (2005): 529–46.
  • “The Marine Biological Laboratory, Seventieth Report, For the Year 1967—Eightieth Year.” The Biological Bulletin 135 (1968): 72.