So how were these individual cells transmitting electrical signals?

So how were these individual cells transmitting electrical signals?By studying and sketching them countless times,Cajal developed a bold, new hypothesis.Instead of electrical signals traveling uninterrupted across a network of fibers,he proposed that signals were somehow jumping from cell to cell in a linear chain of activation.The idea that electrical signals could travel this way was completely unheard of when Cajal proposed it in 1889.However his massive collection of drawings supported his hypothesis from every angle.And in the mid-1900s, electron microscopy further supported this idea by revealing a membrane around each nerve cell keeping it separate from its neighbors.