Final answer:
The reference materials provided do not specify who is credited with developing local anesthesia using hypodermic syringes, but they note William Morton's pioneering use of ether and the discovery of cocaine as a local anesthetic. Alexander Wood and Carl Koller are key figures in the history of anesthesia and hypodermic syringe use.
Step-by-step explanation:
The individual credited with the development of local anesthesia using hypodermic syringes is not mentioned in the provided reference material. However, the material does note that William Morton, a Boston dentist, introduced diethyl ether as an anesthetic in 1846, which marked the beginning of the use of anesthetics in surgeries, although this was general anesthesia rather than local. The first local anesthetic to be discovered was cocaine, and this was an important step in the evolution of surgical anesthesia. It's worth noting that Alexander Wood is often credited with pioneering the use of hypodermic syringes for the administration of drugs, whereas Carl Koller was the one who recognized the use of cocaine for anesthesia in ophthalmic surgery. However, the development of local anesthesia as we know it now, including the use of hypodermic syringes, involves numerous individuals and innovations over time.