Invalid Feeders (aka: feeding cups, nursing cups and/or sick feeders)
They came with many different shaped spouts,
many different shaped handles,
and many different shaped cup designs.
With regards to spouts, but depending on the cup's manufacture, the general opinion that was shared with me when I started collecting is that straight spouts were introduced first and then curved and shorter spouts. With that said I found many exceptions. For instance the Isleworth feeder located in the very top row in the middle (with the two wings, one on each side) was manufactured in the 18th Century but it had a curved spout.
Above is the Kirby Feeding Cup which came in two parts.
Please look at the Photo Library as it contains an extremely large inventory of wonderfully representative samples to enjoy and compare.